TY - GEN A1 - Schaefer, Laura A1 - Dech, Silas A1 - Wolff, Lara Luisa A1 - Bittmann, Frank T1 - Emotional Imagery Influences the Adaptive Force in Young Women BT - Unpleasant Imagery Reduces Instantaneously the Muscular Holding Capacity T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe N2 - The link between emotions and motor function has been known for decades but is still not clarified. The Adaptive Force (AF) describes the neuromuscular capability to adapt to increasing forces and was suggested to be especially vulnerable to interfering inputs. This study investigated the influence of pleasant an unpleasant food imagery on the manually assessed AF of elbow and hip flexors objectified by a handheld device in 12 healthy women. The maximal isometric AF was significantly reduced during unpleasant vs. pleasant imagery and baseline (p < 0.001, dz = 0.98–1.61). During unpleasant imagery, muscle lengthening started at 59.00 ± 22.50% of maximal AF, in contrast to baseline and pleasant imagery, during which the isometric position could be maintained mostly during the entire force increase up to ~97.90 ± 5.00% of maximal AF. Healthy participants showed an immediately impaired holding function triggered by unpleasant imagery, presumably related to negative emotions. Hence, AF seems to be suitable to test instantaneously the effect of emotions on motor function. Since musculoskeletal complaints can result from muscular instability, the findings provide insights into the understanding of the causal chain of linked musculoskeletal pain and mental stress. A case example (current stress vs. positive imagery) suggests that the approach presented in this study might have future implications for psychomotor diagnostics and therapeutics. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 816 KW - Adaptive Force KW - maximal isometric Adaptive Force KW - holding capability KW - neuromuscular adaptation KW - motor control KW - pleasant and unpleasant imagery KW - emotions KW - emotional imagery KW - manual muscle test Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-582014 SN - 1866-8364 IS - 816 ER - TY - JOUR A1 - Schaefer, Laura A1 - Dech, Silas A1 - Wolff, Lara Luisa A1 - Bittmann, Frank T1 - Emotional Imagery Influences the Adaptive Force in Young Women BT - Unpleasant Imagery Reduces Instantaneously the Muscular Holding Capacity JF - Brain Sciences N2 - The link between emotions and motor function has been known for decades but is still not clarified. The Adaptive Force (AF) describes the neuromuscular capability to adapt to increasing forces and was suggested to be especially vulnerable to interfering inputs. This study investigated the influence of pleasant an unpleasant food imagery on the manually assessed AF of elbow and hip flexors objectified by a handheld device in 12 healthy women. The maximal isometric AF was significantly reduced during unpleasant vs. pleasant imagery and baseline (p < 0.001, dz = 0.98–1.61). During unpleasant imagery, muscle lengthening started at 59.00 ± 22.50% of maximal AF, in contrast to baseline and pleasant imagery, during which the isometric position could be maintained mostly during the entire force increase up to ~97.90 ± 5.00% of maximal AF. Healthy participants showed an immediately impaired holding function triggered by unpleasant imagery, presumably related to negative emotions. Hence, AF seems to be suitable to test instantaneously the effect of emotions on motor function. Since musculoskeletal complaints can result from muscular instability, the findings provide insights into the understanding of the causal chain of linked musculoskeletal pain and mental stress. A case example (current stress vs. positive imagery) suggests that the approach presented in this study might have future implications for psychomotor diagnostics and therapeutics. KW - Adaptive Force KW - maximal isometric Adaptive Force KW - holding capability KW - neuromuscular adaptation KW - motor control KW - pleasant and unpleasant imagery KW - emotions KW - emotional imagery KW - manual muscle test Y1 - 2022 U6 - https://doi.org/10.3390/brainsci12101318 SN - 2076-3425 VL - 12 IS - 10 PB - MDPI CY - Basel, Schweiz ER - TY - JOUR A1 - Schaefer, Laura A1 - Dech, Silas A1 - Bittmann, Frank T1 - Adaptive force and emotionally related imaginations BT - Preliminary results suggest a reduction of the maximal holding capacity as reaction to disgusting food imagination JF - Heliyon N2 - The link between emotions and motor control has been discussed for years. The measurement of the Adaptive Force (AF) provides the possibility to get insights into the adaptive control of the neuromuscular system in reaction to external forces. It was hypothesized that the holding isometric AF is especially vulnerable to disturbing inputs. Here, the behavior of the AF under the influence of positive (tasty) vs. negative (disgusting) food imaginations was investigated. The AF was examined in n = 12 cases using an objectified manual muscle test of the hip flexors, elbow flexors or pectoralis major muscle, performed by one of two experienced testers while the participants imagined their most tasty or most disgusting food. The reaction force and the limb position were measured by a handheld device. While the slope of force rises and the maximal AF did not differ significantly between tasty and disgusting imaginations (p > 0.05), the maximal isometric AF was significantly lower and the AF at the onset of oscillations was significantly higher under disgusting vs. tasty imaginations (both p = 0.001). A proper length tension control of muscles seems to be a crucial functional parameter of the neuromuscular system which can be impaired instantaneously by emotionally related negative imaginations. This might be a potential approach to evaluate somatic reactions to emotions. KW - Adaptive Force KW - Isometric Adaptive Force KW - Holding capacity KW - Holding KW - isometric muscle action KW - Imaginations KW - Emotions KW - Motor control KW - Functional weakness KW - Manual muscle test Y1 - 2021 U6 - https://doi.org/10.1016/j.heliyon.2021.e07827 SN - 2405-8440 VL - 7 IS - 8 PB - Elsevier CY - London ER - TY - JOUR A1 - Schaefer, Laura A1 - Dech, Silas A1 - Aehle, Markus A1 - Bittmann, Frank T1 - Disgusting odours affect the characteristics of the adaptive force in contrast to neutral and pleasant odours JF - Scientific Reports N2 - The olfactomotor system is especially investigated by examining the sniffing in reaction to olfactory stimuli. The motor output of respiratory-independent muscles was seldomly considered regarding possible influences of smells. The Adaptive Force (AF) characterizes the capability of the neuromuscular system to adapt to external forces in a holding manner and was suggested to be more vulnerable to possible interfering stimuli due to the underlying complex control processes. The aim of this pilot study was to measure the effects of olfactory inputs on the AF of the hip and elbow flexors, respectively. The AF of 10 subjects was examined manually by experienced testers while smelling at sniffing sticks with neutral, pleasant or disgusting odours. The reaction force and the limb position were recorded by a handheld device. The results show, inter alia, a significantly lower maximal isometric AF and a significantly higher AF at the onset of oscillations by perceiving disgusting odours compared to pleasant or neutral odours (p < 0.001). The adaptive holding capacity seems to reflect the functionality of the neuromuscular control, which can be impaired by disgusting olfactory inputs. An undisturbed functioning neuromuscular system appears to be characterized by a proper length tension control and by an earlier onset of mutual oscillations during an external force increase. This highlights the strong connection of olfaction and motor control also regarding respiratory-independent muscles. Y1 - 2021 U6 - https://doi.org/10.1038/s41598-021-95759-0 SN - 2045-2322 VL - 11 SP - 1 EP - 16 PB - Springer Nature CY - London ER - TY - GEN A1 - Schaefer, Laura A1 - Dech, Silas A1 - Aehle, Markus A1 - Bittmann, Frank T1 - Disgusting odours affect the characteristics of the Adaptive Force in contrast to neutral and pleasant odours T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe N2 - The olfactomotor system is especially investigated by examining the sniffing in reaction to olfactory stimuli. The motor output of respiratory-independent muscles was seldomly considered regarding possible influences of smells. The Adaptive Force (AF) characterizes the capability of the neuromuscular system to adapt to external forces in a holding manner and was suggested to be more vulnerable to possible interfering stimuli due to the underlying complex control processes. The aim of this pilot study was to measure the effects of olfactory inputs on the AF of the hip and elbow flexors, respectively. The AF of 10 subjects was examined manually by experienced testers while smelling at sniffing sticks with neutral, pleasant or disgusting odours. The reaction force and the limb position were recorded by a handheld device. The results show, inter alia, a significantly lower maximal isometric AF and a significantly higher AF at the onset of oscillations by perceiving disgusting odours compared to pleasant or neutral odours (p < 0.001). The adaptive holding capacity seems to reflect the functionality of the neuromuscular control, which can be impaired by disgusting olfactory inputs. An undisturbed functioning neuromuscular system appears to be characterized by a proper length tension control and by an earlier onset of mutual oscillations during an external force increase. This highlights the strong connection of olfaction and motor control also regarding respiratory-independent muscles. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 758 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-548980 SN - 1866-8364 SP - 1 EP - 16 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Schaefer, Laura A1 - Carnarius, Friederike A1 - Dech, Silas A1 - Bittmann, Frank T1 - Repeated measurements of Adaptive Force BT - Maximal holding capacity differs from other maximal strength parameters and preliminary characteristics for non-professional strength vs. endurance athletes T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe N2 - The Adaptive Force (AF) reflects the neuromuscular capacity to adapt to external loads during holding muscle actions and is similar to motions in real life and sports. The maximal isometric AF (AFisomax) was considered to be the most relevant parameter and was assumed to have major importance regarding injury mechanisms and the development of musculoskeletal pain. The aim of this study was to investigate the behavior of different torque parameters over the course of 30 repeated maximal AF trials. In addition, maximal holding vs. maximal pushing isometric muscle actions were compared. A side consideration was the behavior of torques in the course of repeated AF actions when comparing strength and endurance athletes. The elbow flexors of n = 12 males (six strength/six endurance athletes, non-professionals) were measured 30 times (120 s rest) using a pneumatic device. Maximal voluntary isometric contraction (MVIC) was measured pre and post. MVIC, AFisomax, and AFmax (maximal torque of one AF measurement) were evaluated regarding different considerations and statistical tests. AFmax and AFisomax declined in the course of 30 trials [slope regression (mean ± standard deviation): AFmax = −0.323 ± 0.263; AFisomax = −0.45 ± 0.45]. The decline from start to end amounted to −12.8% ± 8.3% (p < 0.001) for AFmax and −25.41% ± 26.40% (p < 0.001) for AFisomax. AF parameters declined more in strength vs. endurance athletes. Thereby, strength athletes showed a rather stable decline for AFmax and a plateau formation for AFisomax after 15 trials. In contrast, endurance athletes reduced their AFmax, especially after the first five trials, and remained on a rather similar level for AFisomax. The maximum of AFisomax of all 30 trials amounted 67.67% ± 13.60% of MVIC (p < 0.001, n = 12), supporting the hypothesis of two types of isometric muscle action (holding vs. pushing). The findings provided the first data on the behavior of torque parameters after repeated isometric–eccentric actions and revealed further insights into neuromuscular control strategies. Additionally, they highlight the importance of investigating AF parameters in athletes based on the different behaviors compared to MVIC. This is assumed to be especially relevant regarding injury mechanisms. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 831 KW - Adaptive Force KW - maximal isometric Adaptive Force KW - holding capacity KW - neuromuscular control KW - strength vs. endurance athletes KW - injury mechanisms KW - repeated adaptive isometric–eccentric muscle action KW - holding (HIMA) and pushing (PIMA) isometric muscle action Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-588030 SN - 1866-8364 IS - 831 ER - TY - JOUR A1 - Schaefer, Laura A1 - Carnarius, Friederike A1 - Dech, Silas A1 - Bittmann, Frank T1 - Repeated measurements of Adaptive Force BT - maximal holding capacity differs from other maximal strength parameters and preliminary characteristics for non-professional strength vs. endurance athletes JF - Frontiers in physiology N2 - The Adaptive Force (AF) reflects the neuromuscular capacity to adapt to external loads during holding muscle actions and is similar to motions in real life and sports. The maximal isometric AF (AFisoₘₐₓ) was considered to be the most relevant parameter and was assumed to have major importance regarding injury mechanisms and the development of musculoskeletal pain. The aim of this study was to investigate the behavior of different torque parameters over the course of 30 repeated maximal AF trials. In addition, maximal holding vs. maximal pushing isometric muscle actions were compared. A side consideration was the behavior of torques in the course of repeated AF actions when comparing strength and endurance athletes. The elbow flexors of n = 12 males (six strength/six endurance athletes, non-professionals) were measured 30 times (120 s rest) using a pneumatic device. Maximal voluntary isometric contraction (MVIC) was measured pre and post. MVIC, AFisoₘₐₓ, and AFₘₐₓ (maximal torque of one AF measurement) were evaluated regarding different considerations and statistical tests. AFₘₐₓ and AFisoₘₐₓ declined in the course of 30 trials [slope regression (mean ± standard deviation): AFₘₐₓ = −0.323 ± 0.263; AFisoₘₐₓ = −0.45 ± 0.45]. The decline from start to end amounted to −12.8% ± 8.3% (p < 0.001) for AFₘₐₓ and −25.41% ± 26.40% (p < 0.001) for AFisoₘₐₓ. AF parameters declined more in strength vs. endurance athletes. Thereby, strength athletes showed a rather stable decline for AFmax and a plateau formation for AFisoₘₐₓ after 15 trials. In contrast, endurance athletes reduced their AFₘₐₓ, especially after the first five trials, and remained on a rather similar level for AFisomax. The maximum of AFisoₘₐₓ of all 30 trials amounted 67.67% ± 13.60% of MVIC (p < 0.001, n = 12), supporting the hypothesis of two types of isometric muscle action (holding vs. pushing). The findings provided the first data on the behavior of torque parameters after repeated isometric–eccentric actions and revealed further insights into neuromuscular control strategies. Additionally, they highlight the importance of investigating AF parameters in athletes based on the different behaviors compared to MVIC. This is assumed to be especially relevant regarding injury mechanisms. KW - Adaptive Force KW - maximal isometric Adaptive Force KW - holding capacity KW - neuromuscular control KW - strength vs. endurance athletes KW - injury mechanisms KW - repeated adaptive isometric–eccentric muscle action KW - holding (HIMA) and pushing (PIMA) isometric muscle action Y1 - 2023 U6 - https://doi.org/10.3389/fphys.2023.1020954 SN - 1664-042X VL - 14 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Muscle oxygenation and time to task failure of submaximal holding and pulling isometric muscle actions and influence of intermittent voluntary muscle twitches T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Background Isometric muscle actions can be performed either by initiating the action, e.g., pulling on an immovable resistance (PIMA), or by reacting to an external load, e.g., holding a weight (HIMA). In the present study, it was mainly examined if these modalities could be differentiated by oxygenation variables as well as by time to task failure (TTF). Furthermore, it was analyzed if variables are changed by intermittent voluntary muscle twitches during weight holding (Twitch). It was assumed that twitches during a weight holding task change the character of the isometric muscle action from reacting (≙ HIMA) to acting (≙ PIMA). Methods Twelve subjects (two drop outs) randomly performed two tasks (HIMA vs. PIMA or HIMA vs. Twitch, n = 5 each) with the elbow flexors at 60% of maximal torque maintained until muscle failure with each arm. Local capillary venous oxygen saturation (SvO2) and relative hemoglobin amount (rHb) were measured by light spectrometry. Results Within subjects, no significant differences were found between tasks regarding the behavior of SvO2 and rHb, the slope and extent of deoxygenation (max. SvO2 decrease), SvO2 level at global rHb minimum, and time to SvO2 steady states. The TTF was significantly longer during Twitch and PIMA (incl. Twitch) compared to HIMA (p = 0.043 and 0.047, respectively). There was no substantial correlation between TTF and maximal deoxygenation independently of the task (r = − 0.13). Conclusions HIMA and PIMA seem to have a similar microvascular oxygen and blood supply. The supply might be sufficient, which is expressed by homeostatic steady states of SvO2 in all trials and increases in rHb in most of the trials. Intermittent voluntary muscle twitches might not serve as a further support but extend the TTF. A changed neuromuscular control is discussed as possible explanation. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 798 KW - Oxygen saturation KW - Microvascular blood filling KW - Isometric contraction KW - Isometric muscle action KW - Holding isometric muscle action KW - Pulling isometric muscle action KW - Pushing isometric muscle action KW - Time to task failure KW - Muscle twitch Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-566878 SN - 1866-8364 SP - 1 EP - 10 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Behavior of oxygen saturation and blood filling in the venous capillary system of the biceps brachii muscle during a fatiguing isometric action T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe 618 N2 - The objective of the study is to develop a better understanding of the capillary circulation in contracting muscles. Ten subjects were measured during a submaximal fatiguing isometric muscle action by use of the O2C spectrophotometer. In all measurements the capillary-venous oxygen saturation of hemoglobin (SvO2) decreases immediately after the start of loading and levels off into a steady state. However, two different patterns (type I and type II) emerged. They differ in the extent of deoxygenation (–10.37 ±2.59 percent points (pp) vs. –33.86 ±17.35 pp, P = .008) and the behavior of the relative hemoglobin amount (rHb). Type I reveals a positive rank correlation of SvO2 and rHb (? = 0.735, P <.001), whereas a negative rank correlation (? = –0.522, P <.001) occurred in type II, since rHb decreases until a reversal point, then increases averagely 13% above the baseline value and levels off into a steady state. The results reveal that a homeostasis of oxygen delivery and consumption during isometric muscle actions is possible. A rough distinction in two types of regulation is suggested. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 618 KW - muscle oxygenation KW - hemoglobin amount KW - isometric muscle action KW - O2C spectrophotometer Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460166 SN - 1866-8364 IS - 618 SP - 79 EP - 87 ER - TY - JOUR A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Behavior of oxygen saturation and blood filling in the venous capillary system of the biceps brachii muscle during a fatiguing isometric action JF - European Journal of Translational Myology N2 - The objective of the study is to develop a better understanding of the capillary circulation in contracting muscles. Ten subjects were measured during a submaximal fatiguing isometric muscle action by use of the O2C spectrophotometer. In all measurements the capillary-venous oxygen saturation of hemoglobin (SvO2) decreases immediately after the start of loading and levels off into a steady state. However, two different patterns (type I and type II) emerged. They differ in the extent of deoxygenation (–10.37 ±2.59 percent points (pp) vs. –33.86 ±17.35 pp, P = .008) and the behavior of the relative hemoglobin amount (rHb). Type I reveals a positive rank correlation of SvO2 and rHb (? = 0.735, P <.001), whereas a negative rank correlation (? = –0.522, P <.001) occurred in type II, since rHb decreases until a reversal point, then increases averagely 13% above the baseline value and levels off into a steady state. The results reveal that a homeostasis of oxygen delivery and consumption during isometric muscle actions is possible. A rough distinction in two types of regulation is suggested. KW - muscle oxygenation KW - hemoglobin amount KW - isometric muscle action KW - O2C spectrophotometer Y1 - 2020 U6 - https://doi.org/10.4081/ejtm.2019.8800 SN - 2037-7460 VL - 30 IS - 1 SP - 79 EP - 87 PB - Unipress CY - Padova ER - TY - GEN A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Assessment of the Adaptive Force of Elbow Extensors in Healthy Subjects Quantified by a Novel Pneumatically Driven Measurement System with Considerations of Its Quality Criteria T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 710 KW - adaptive force KW - neuromuscular functionality KW - sensorimotor control KW - isometric muscle action KW - eccentric muscle action KW - maximal voluntary contraction KW - adaptive holding capacity KW - reliability KW - validity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-510950 SN - 1866-8364 IS - 710 ER - TY - JOUR A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Assessment of the adaptive force of Elbow extensors in healthy subjects quantified by a novel pneumatically driven measurement system with considerations of its quality criteria JF - Diagnostics : open access journal N2 - Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function. KW - adaptive force KW - sensorimotor control KW - isometric muscle action KW - eccentric muscle action KW - maximal voluntary contraction KW - adaptive holding capacity KW - reliability KW - validity KW - neuromuscular functionality Y1 - 2021 U6 - https://doi.org/10.3390/diagnostics11060923 SN - 2075-4418 VL - 11 IS - 6 PB - MDPI CY - Basel ER - TY - GEN A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Muscle oxygenation level might trigger the regulation of capillary venous blood filling during fatiguing isometric muscle actions T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - The regulation of oxygen and blood supply during isometric muscle actions is still unclear. Recently, two behavioral types of oxygen saturation (SvO2) and relative hemoglobin amount (rHb) in venous microvessels were described during a fatiguing holding isometric muscle action (HIMA) (type I: nearly parallel behavior of SvO2 and rHb; type II: partly inverse behavior). The study aimed to ascertain an explanation of these two regulative behaviors. Twelve subjects performed one fatiguing HIMA trial with each arm by weight holding at 60% of the maximal voluntary isometric contraction (MVIC) in a 90° elbow flexion. Six subjects additionally executed one fatiguing PIMA trial by pulling on an immovable resistance with 60% of the MVIC with each side and same position. Both regulative types mentioned were found during HIMA (I: n = 7, II: n = 17) and PIMA (I: n = 3, II: n = 9). During the fatiguing measurements, rHb decreased initially and started to increase in type II at an average SvO2-level of 58.75 ± 2.14%. In type I, SvO2 never reached that specific value during loading. This might indicate the existence of a threshold around 59% which seems to trigger the increase in rHb and could explain the two behavioral types. An approach is discussed to meet the apparent incompatibility of an increased capillary blood filling (rHb) despite high intramuscular pressures which were found by other research groups during isometric muscle actions. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 723 KW - muscle oxygen saturation KW - hemoglobin amount KW - isometric muscle action KW - O2C spectrophotometer KW - capillary recruitment KW - blood flow KW - holding isometric muscle action (HIMA) KW - pulling isometric muscle action (PIMA) Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-524078 SN - 1866-8364 IS - 11 ER - TY - JOUR A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Muscle oxygenation level might trigger the regulation of capillary venous blood filling during fatiguing isometric muscle actions JF - Diagnostics : open access journal N2 - The regulation of oxygen and blood supply during isometric muscle actions is still unclear. Recently, two behavioral types of oxygen saturation (SvO(2)) and relative hemoglobin amount (rHb) in venous microvessels were described during a fatiguing holding isometric muscle action (HIMA) (type I: nearly parallel behavior of SvO(2) and rHb; type II: partly inverse behavior). The study aimed to ascertain an explanation of these two regulative behaviors. Twelve subjects performed one fatiguing HIMA trial with each arm by weight holding at 60% of the maximal voluntary isometric contraction (MVIC) in a 90 & DEG; elbow flexion. Six subjects additionally executed one fatiguing PIMA trial by pulling on an immovable resistance with 60% of the MVIC with each side and same position. Both regulative types mentioned were found during HIMA (I: n = 7, II: n = 17) and PIMA (I: n = 3, II: n = 9). During the fatiguing measurements, rHb decreased initially and started to increase in type II at an average SvO(2)-level of 58.75 & PLUSMN; 2.14%. In type I, SvO(2) never reached that specific value during loading. This might indicate the existence of a threshold around 59% which seems to trigger the increase in rHb and could explain the two behavioral types. An approach is discussed to meet the apparent incompatibility of an increased capillary blood filling (rHb) despite high intramuscular pressures which were found by other research groups during isometric muscle actions. KW - muscle oxygen saturation KW - hemoglobin amount KW - isometric muscle action KW - O2C spectrophotometer KW - capillary recruitment KW - blood flow KW - holding KW - isometric muscle action (HIMA) KW - pulling isometric muscle action (PIMA) Y1 - 2021 U6 - https://doi.org/10.3390/diagnostics11111973 SN - 2075-4418 VL - 11 IS - 11 PB - MDPI CY - Basel ER - TY - JOUR A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Muscle oxygenation and time to task failure of submaximal holding and pulling isometric muscle actions and influence of intermittent voluntary muscle twitches JF - BMC Sports Science, Medicine and Rehabilitation N2 - Background Isometric muscle actions can be performed either by initiating the action, e.g., pulling on an immovable resistance (PIMA), or by reacting to an external load, e.g., holding a weight (HIMA). In the present study, it was mainly examined if these modalities could be differentiated by oxygenation variables as well as by time to task failure (TTF). Furthermore, it was analyzed if variables are changed by intermittent voluntary muscle twitches during weight holding (Twitch). It was assumed that twitches during a weight holding task change the character of the isometric muscle action from reacting (≙ HIMA) to acting (≙ PIMA). Methods Twelve subjects (two drop outs) randomly performed two tasks (HIMA vs. PIMA or HIMA vs. Twitch, n = 5 each) with the elbow flexors at 60% of maximal torque maintained until muscle failure with each arm. Local capillary venous oxygen saturation (SvO2) and relative hemoglobin amount (rHb) were measured by light spectrometry. Results Within subjects, no significant differences were found between tasks regarding the behavior of SvO2 and rHb, the slope and extent of deoxygenation (max. SvO2 decrease), SvO2 level at global rHb minimum, and time to SvO2 steady states. The TTF was significantly longer during Twitch and PIMA (incl. Twitch) compared to HIMA (p = 0.043 and 0.047, respectively). There was no substantial correlation between TTF and maximal deoxygenation independently of the task (r = − 0.13). Conclusions HIMA and PIMA seem to have a similar microvascular oxygen and blood supply. The supply might be sufficient, which is expressed by homeostatic steady states of SvO2 in all trials and increases in rHb in most of the trials. Intermittent voluntary muscle twitches might not serve as a further support but extend the TTF. A changed neuromuscular control is discussed as possible explanation. KW - Oxygen saturation KW - Microvascular blood filling KW - Isometric contraction KW - Isometric muscle action KW - Holding isometric muscle action KW - Pulling isometric muscle action KW - Pushing isometric muscle action KW - Time to task failure KW - Muscle twitch Y1 - 2022 U6 - https://doi.org/10.1186/s13102-022-00447-9 SN - 1758-2555 VL - 55 SP - 1 EP - 10 PB - Springer Nature CY - London ER - TY - JOUR A1 - Dech, Silas A1 - Bittmann, Frank A1 - Schaefer, Laura T1 - Muscle oxygenation level might trigger the regulation of capillary venous blood filling during fatiguing isometric muscle actions JF - Diagnostics N2 - The regulation of oxygen and blood supply during isometric muscle actions is still unclear. Recently, two behavioral types of oxygen saturation (SvO2) and relative hemoglobin amount (rHb) in venous microvessels were described during a fatiguing holding isometric muscle action (HIMA) (type I: nearly parallel behavior of SvO2 and rHb; type II: partly inverse behavior). The study aimed to ascertain an explanation of these two regulative behaviors. Twelve subjects performed one fatiguing HIMA trial with each arm by weight holding at 60% of the maximal voluntary isometric contraction (MVIC) in a 90° elbow flexion. Six subjects additionally executed one fatiguing PIMA trial by pulling on an immovable resistance with 60% of the MVIC with each side and same position. Both regulative types mentioned were found during HIMA (I: n = 7, II: n = 17) and PIMA (I: n = 3, II: n = 9). During the fatiguing measurements, rHb decreased initially and started to increase in type II at an average SvO2-level of 58.75 ± 2.14%. In type I, SvO2 never reached that specific value during loading. This might indicate the existence of a threshold around 59% which seems to trigger the increase in rHb and could explain the two behavioral types. An approach is discussed to meet the apparent incompatibility of an increased capillary blood filling (rHb) despite high intramuscular pressures which were found by other research groups during isometric muscle actions. KW - muscle oxygen saturation KW - hemoglobin amount KW - isometric muscle action KW - O2C spectrophotometer KW - capillary recruitment KW - blood flow KW - holding isometric muscle action (HIMA) KW - pulling isometric muscle action (PIMA) Y1 - 2021 U6 - https://doi.org/10.3390/diagnostics11111973 SN - 2075-4418 VL - 11 IS - 11 PB - MDPI CY - Basel ER - TY - THES A1 - Dech, Silas T1 - Isometric muscle function T1 - Die Isometrische Muskelfunktion BT - with specific respect to oxygen supply and adaptive force BT - unter besonderer Betrachtung der Sauerstoffversorgung und Adaptiven Kraft N2 - The cumulative dissertation consists of four original articles. These considered isometric muscle ac-tions in healthy humans from a basic physiological view (oxygen and blood supply) as well as possibilities of their distinction. It includes a novel approach to measure a specific form of isometric hold-ing function which has not been considered in motor science so far. This function is characterized by an adaptation to varying external forces with particular importance in daily activities and sports. The first part of the research program analyzed how the biceps brachii muscle is supplied with oxygen and blood by adapting to a moderate constant load until task failure (publication 1). In this regard, regulative mechanisms were investigated in relation to the issue of presumably compressed capillaries due to high intramuscular pressures (publication 2). Furthermore, it was examined if oxygenation and time to task failure (TTF) differs compared to an-other isometric muscle function (publication 3). This function is mainly of diagnostic interest by measuring the maximal voluntary isometric contraction (MVIC) as a gold standard. For that, a person pulls on or pushes against an insurmountable resistance. However, the underlying pulling or pushing form of isometric muscle action (PIMA) differs compared to the holding one (HIMA). HIMAs have mainly been examined by using constant loads. In order to quantify the adaptability to varying external forces, a new approach was necessary and considered in the second part of the research program. A device was constructed based on a previously developed pneumatic measurement system. The device should have been able to measure the Adaptive Force (AF) of elbow ex-tensor muscles. The AF determines the adaptability to increasing external forces under isometric (AFiso) and eccentric (AFecc) conditions. At first, it was questioned if these parameters can be relia-bly assessed by use of the new device (publication 4). Subsequently, the main research question was investigated: Is the maximal AFiso a specific and independent variable of muscle function in comparison to the MVIC? Furthermore, both research parts contained a sub-question of how results can be influenced. Parameters of local oxygen saturation (SvO2) and capillary blood filling (rHb) were non-invasively recorded by a spectrophotometer during maximal and submaximal HIMAs and PIMAs. These were the main findings: Under load, SvO2 and rHb always adjusted into a steady state after an initial decrease. Nevertheless, their behavior could roughly be categorized into two types. In type I, both parameters behaved nearly parallel to each other. In contrast, their progression over time was partly inverse in type II. The inverse behavior probably depends on the level of deoxygenation since rHb increased reliably at a suggested threshold of about 59% SvO2. This triggered mechanism and the found homeostatic steady states seem to be in conflict with the concept of mechanically compressed capillaries and consequently with a restricted blood flow. Anatomical configuration of blood vessels might provide one hypothetical explanation of how blood flow might be maintained. HIMA and PIMA did not differ regarding oxygenation and allocation to the described types. The TTF tended to be longer during PIMA. As a sub-question, oxygenation and TTF were compared between (HIMA) and intermittent voluntary muscle twitches during a weight holding task. TTF but not oxygenation differed significantly (Twitch > HIMA). A changed neuromuscular control might serve as a speculative explanation of how the results can be explained. This is supported by the finding that the TTF did not correlate significantly with the extent of deoxygenation irrespective of the performed task (HIMA, PIMA or Twitch). Other neuromuscular aspects of muscle function were considered in second part of the re-search program. The new device mentioned above detected different force capacities within four trials at two days each. Among AF measurements, the functional counterpart of a concentric muscle action merging into an isometric one was analyzed in comparison to the MVIC. Based on the results, it can be assumed that a prior concentric muscle action does not influence the MVIC. However, the results were inconsistent and possibly influenced by systematic errors. In con-trast, maximal variables of the AF (AFisomax and AFeccmax) could be measured in a reliable way which is indicated by a high test-retest reliability. Despite substantial correlations between force variables, the AFisomax differed significantly from MVIC and AFmax, which was identical with AFeccmax in almost all cases. Moreover, AFisomax revealed the highest variability between trials. These results indicate that maximal force capacities should be assessed separately. The adaptive holding capacity of a muscle can be lower compared to a commonly determined MVIC. This is of relevance since muscles frequently need to respond adequately to external forces. If their response does not correspond to the external impact, the muscle is forced to lengthen. In this scenario, joints are not completely stabilized and an injury may occur. This outlined issue should be addressed in future research in the field of sport and health sciences. At last, the dissertation presents another possibility to quantify the AFisomax by use of a handheld device applied in combination with a manual muscle test. This assessment delivers a more practical way for clinical purposes. N2 - Die kumulative Dissertation setzt sich im Kern aus vier Originalartikel zusammen. Diese betrachten isometrische Muskelaktionen beim gesunden Menschen aus grundlegender physiologischer Sicht (Sauerstoff- und Blutversorgung) sowie Möglichkeiten ihrer Unterscheidung. Sie beinhaltet einen neuartigen Ansatz zur Messung einer spezifischen Form der isometrischen Haltefunktion, die bisher in der Bewegungswissenschaft nicht berücksichtigt wurde. Diese Funktion ist durch eine Anpassung an variierende äußere Kräfte gekennzeichnet, die bei täglichen Aktivitäten und im Sport von besonderer Bedeutung ist. Im ersten Teil des Forschungsprogramms wurde untersucht, wie der M. biceps brachii mit Sauerstoff und Blut versorgt wird, indem er sich an eine moderate konstante Belastung bis zum Versagen der Aufgabe anpasst (Publikation 1). In diesem Zusammenhang wurden Regulationsmechanismen in Bezug auf die Problematik der hohe intramuskulären Drücke betrachtet, die theoretisch zu einer Komprimierung der Kapillaren führen (Publikation 2). Darüber hinaus wurde untersucht, ob sich die Sauerstoffversorgung und die Zeit bis zum Versagen der Aufgabe (time to task failure, TTF) im Vergleich zu einer anderen isometrischen Muskelfunktion unterscheiden (Publikation 3). Diese Funktion ist hauptsächlich von diagnostischem Interesse, indem die maximale willkürliche isometrische Kontraktion (MVIC) als Goldstandard gemessen wird. Dabei zieht oder drückt eine Person an/gegen einen unüberwindbaren Widerstand. Die zugrundeliegende ziehende oder drückende Form der isometrischen Muskelaktion (pushing or pulling isometric muscle action, PIMA) unterscheidet sich jedoch von der haltenden Form (holding isometric muscle action, HIMA). HIMAs wurden bisher hauptsächlich unter Verwendung konstanter Lasten untersucht. Um die Anpassungsfähigkeit an variierende äußere Kräfte zu quantifizieren, war ein neuer Ansatz erforderlich, der im zweiten Teil des Forschungsprogramms berücksichtigt wurde. Dazu wurde ein Gerät konstruiert, das auf einem zuvor entwickelten pneumatischen Messsystem basiert. Das Gerät sollte in der Lage sein, die Adaptive Force (AF) der Ellbogenstreckmuskulatur zu messen. Die AF bestimmt die Anpassungsfähigkeit an steigende äußere Kräfte unter isometrischen (AFiso) und exzentrischen AFecc) Bedingungen. Zunächst wurde die Frage gestellt, ob diese Parameter mit dem neuen Gerät zuverlässig erfasst werden können (Publikation 4). Anschließend wurde die Hauptforschungsfrage untersucht: Ist die maximale AFiso eine spezifische und unabhängige Variable der Muskelfunktion im Vergleich zur MVIC? Darüber hinaus enthielten beide Forschungsteile eine Unterfrage, wie die Ergebnisse beeinflusst werden können. Die Parameter der lokalen Sauerstoffsättigung (SvO2) und der Kapillarblutfüllung (rHb) wurden während der maximaler und submaximaler HIMAs und PIMAs nicht-invasiv mit einem Spektrophotometer erfasst. Dies waren die wichtigsten Ergebnisse: Unter Belastung pendelten sich SvO2 und rHb nach einem anfänglichen Abfall immer in einen stabilen Zustand ein. Dennoch konnte ihr Verhalten grob in zwei Typen eingeteilt werden. Bei Typ I verhielten sich beide Parameter nahezu parallel zueinander. Im Gegensatz dazu war ihr zeitlicher Verlauf bei Typ II teilweise invers. Das umgekehrte Verhalten hängt wahrscheinlich vom Grad der Desoxygenierung ab, da der rHb-Wert zuverlässig bei einem Schwellenwert von etwa 59 % SvO2 anstieg. Diser Auslösemechanismus und die gefundenen homöostatischen Gleichgewichtszustände scheinen im Widerspruch zu dem Konzept mechanisch komprimierter Kapillaren und folglich zu einem eingeschränkten Blutfluss zu stehen. Die anatomische Lage und Verlauf der Blutgefäße könnte eine hypothetische Erklärung dafür liefern, wie der Blutfluss aufrechterhalten werden könnte. HIMA und PIMA unterschieden sich nicht hinsichtlich der Sauerstoffzufuhr und der Zuordnung zu den beschriebenen Typen. Die TTF war bei PIMA tendenziell länger. Als Unterfrage wurden Oxygenierung und TTF zwischen (HIMA) und intermittierenden freiwilligen Muskelzuckungen während einer Gewichthalteaufgabe verglichen. Die TTF, nicht aber die Oxygenierung, unterschied sich signifikant (Zuckung > HIMA). Eine veränderte neuromuskuläre Kontrolle könnte als spekulative Erklärung für die Ergebnisse dienen. Dies wird durch die Feststellung unterstützt, dass die TTF unabhängig von der durchgeführten Aufgabe (HIMA, PIMA oder Zuckung) nicht signifikant mit dem Ausmaß der Desoxygenierung korrelierte. Andere neuromuskuläre Aspekte der Muskelfunktion wurden im zweiten Teil des Forschungsprogramms berücksichtigt. Mit dem oben erwähnten neuen Gerät wurden innerhalb von vier Versuchen an jeweils zwei Tagen unterschiedliche Kraftkapazitäten ermittelt. Unter den AF-Messungen wurde der funktionelle Gegenpart einer konzentrischen Muskelaktion, die in eine isometrische übergeht, im Vergleich zur MVIC analysiert. Aufgrund der Ergebnisse kann davon ausgegangen werden, dass eine vorherige konzentrische Muskelaktion die MVIC nicht beeinflusst. Allerdings waren die Ergebnisse inkonsistent und möglicherweise durch systematische Fehler beeinflusst. Im Gegensatz dazu konnten die Variablen der AF (AFisomax und AFeccmax) zuverlässig gemessen werden, was sich durch eine hohe Test-Retest-Reliabilität zeigte. Trotz erheblicher Korrelationen zwischen den Kraftvariablen unterschied sich AFisomax signifikant von MVIC und AFmax, welcher in fast allen Fällen mit AFeccmax identisch war. Außerdem wies AFisomax die höchste Variabilität zwischen den Versuchen auf. Diese Ergebnisse deuten darauf hin, dass diese Maximalkräfte separat erfasst werden sollten. Die adaptive Haltekapazität eines Muskels kann im Vergleich zu einer allgemein ermittelten MVIC niedriger sein. Dies ist von Bedeutung, da Muskeln häufig angemessen auf äußere Kräfte reagieren müssen. Wenn ihre Reaktion nicht der äußeren Einwirkung entspricht, ist der Muskel gezwungen, sich zu verlängern. In diesem Fall werden die Gelenke nicht vollständig stabilisiert und es kann zu einer Verletzung kommen. Dieses Thema sollte in der künftigen Forschung im Bereich der Sport- und Gesundheitswissenschaften betrachtet werden. Schließlich wird in der Dissertation eine weitere Möglichkeit zur Quantifizierung der AFisomax mit Hilfe eines Handgeräts in Kombination mit einem manuellen Muskeltest vorgestellt. Diese Bewertung bietet eine praktischere Alternative für klinische Zwecke. KW - isometric contraction KW - holding isometric muscle action KW - neuromuscular functionality KW - muscle oxygen saturation KW - microvascular blood filling KW - muscle blood flow KW - time to task failure KW - haltende isometrische Muskelaktion KW - isometrische Kontraktion KW - Kapillarblutfüllung KW - Muskeldurchblutung KW - muskuläre Sauerstoffsättigung KW - neuomuskuläre Funktionalität KW - Kraftausdauer Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-571265 ER - TY - THES A1 - Dech, Silas T1 - Therapeutisches Klettern nach dem Potsdamer Modell bei Jugendlichen mit Skoliose T1 - Therapeutic climbing according to the Potsdam Model in adolescents with scoliosis BT - ein Trainingskonzept mit Übungskatalog und Vorbereitung einer randomisierten kontrollierten Studie BT - a training concept with an exercise booklet and preparation of a randomized controlled trial N2 - Bisher ist die Ursache für die Entstehung der meisten Skoliosen noch ungeklärt und damit eine kausale Behandlung der Betroffenen unmöglich. Die vorliegende Arbeit geht davon aus, dass der Auslöser für die sogenannte idiopathische Skoliose eine funktionelle Störung von Muskeln ist, die sich in einer verminderten relativen Haltekraft äußert. Durch gezielte willkürliche Muskelanspannungen könnte es möglich sein, kompensatorisch auf die Deformität einzuwirken, um damit ein Fortschreiten zu verhindern bzw. sogar eine Regression hervorzurufen. Insbesondere Patientengruppen mit einem hohen Progressionsrisiko, wie Jugendliche im Wachstumsalter, könnten davon profitieren. Ein Muskeltraining kann mit unterschiedlichsten Hilfsmitteln und Methoden erfolgen. Eine Möglichkeit bietet auch das Klettern. Im Kern wird daher ein Trainingskonzept zum Therapeutischen Klettern bei Jugendlichen mit Skoliose vorgestellt. Dabei beruft sich der Autor auf das Potsdamer Modell. Dieses Modell erlaubt es, gezielte Kraftübungen systematisiert an der Kletterwand in Absprunghöhe umzusetzen. Materielle Sicherungsmaßnahmen sind dadurch nicht erforderlich und eventuell notwendige Korrekturen bzw. Hilfestellungen können direkt erfolgen. Hauptinhalt eines Trainings nach dem vorgestellten Konzept sind spielerische Bewegungserfahrung innerhalb der Sportart Klettern und ein Systembouldertraining. In einem beigefügten Übungskatalog werden für letzteres Möglichkeiten der praktischen Umsetzun-gen gegeben. Die Übungen fokussieren sich auf die Aktivierung und das Training wirbelkörperdero-tierender Muskeln. Im Hauptteil einer Trainingseinheit können sie dann in Kombination mit der Kor-rektur der Seitverbiegung und des sagittalen Profils (3D Autokorrektur) unter Aufsicht eines geschul-ten Therapeuten durchgeführt werden. Die Arbeit erhebt den Anspruch, einem Leser vom Fach, die Auswahl der Übungen und die darin enthaltene individuelle Anpassung an den Patienten aus funktionell-anatomischer Sicht zu begründen. In naher Zukunft wird das Konzept in einer randomisiert kontrollierten Studie untersucht. Alle notwendigen Vorbereitungen wurden im Rahmen dieser Arbeit getroffen. N2 - To date, the cause of most scolioses is still unclear and, therefore, causal treatment is impossible. The present work assumes that the trigger for a so-called idiopathic scoliosis is a functional disorder of muscles expressed by a reduced relative holding force. Special voluntary muscle actions might have a compensatory effect on the deformity and preventing a progression or even inducing a regression. In particular, patients with a high risk of progression, such as adolescents, could benefit from these. There are many different muscle training regimes. Climbing also offers a possibility. Thus, a training concept for therapeutic climbing in adolescents with scoliosis is presented. The author refers to the Potsdam Model, thereby. This model makes it possible to systematically implement special strength exercises on the climbing wall at jumping height. Climbing protections are not necessary and any therapeutic corrections or assistance can be given directly. The main contents of the concept are playful experiences of climbing movements and a systematical boulder training. For the latter, exercises are given in an enclosed booklet. The exercises focus on the activation and training of muscles which derotate the spinal column. In the main part of a training session, they can be performed in combination with a correction of lateral bending and sagittal profile (3D autocorrection) by supervision of a trained therapist. The work claims to explain the selection of the exercises and the individual adaptation to the patient from a functional-anatomical point of view to health professionals. In the near future, the concept will be investigated in a randomized controlled trial. All necessary preparations have been made in the context of this work. KW - Klettertherapie KW - Sporttherapie KW - adoleszente idiopathische Skoliose KW - skoliosespezifische Übungen KW - Bouldern KW - climbing therapy KW - exercise therapy KW - adolescent idiopathic scoliosis KW - scoliosis-specific exercises KW - bouldering Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-532072 ER - TY - JOUR A1 - Bittmann, Frank A1 - Dech, Silas A1 - Schaefer, Laura T1 - Another way to confuse motor control BT - manual technique supposed to shorten muscle spindles reduces the muscular holding stability in the sense of adaptive force in male soccer players JF - Brain Sciences N2 - Sensorimotor control can be impaired by slacked muscle spindles. This was shown for reflex responses and, recently, also for muscular stability in the sense of Adaptive Force (AF). The slack in muscle spindles was generated by contracting the lengthened muscle followed by passive shortening. AF was suggested to specifically reflect sensorimotor control since it requires tension-length control in adaptation to an increasing load. This study investigated AF parameters in reaction to another, manually performed slack procedure in a preselected sample (n = 13). The AF of 11 elbow and 12 hip flexors was assessed by an objectified manual muscle test (MMT) using a handheld device. Maximal isometric AF was significantly reduced after manual spindle technique vs. regular MMT. Muscle lengthening started at 64.93 & PLUSMN; 12.46% of maximal voluntary isometric contraction (MVIC). During regular MMT, muscle length could be maintained stable until 92.53 & PLUSMN; 10.12% of MVIC. Hence, muscular stability measured by AF was impaired after spindle manipulation. Force oscillations arose at a significantly lower level for regular vs. spindle. This supports the assumption that they are a prerequisite for stable adaptation. Reduced muscular stability in reaction to slack procedures is considered physiological since sensory information is misled. It is proposed to use slack procedures to test the functionality of the neuromuscular system, which is relevant for clinical practice. KW - maximal isometric Adaptive Force KW - holding capacity KW - muscle stability KW - muscle instability KW - neuromuscular functioning KW - neuromuscular control KW - motor control KW - muscle spindle KW - muscle physiology KW - regulatory physiology Y1 - 2023 U6 - https://doi.org/10.3390/brainsci13071105 SN - 2076-3425 VL - 13 IS - 7 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bittmann, Frank A1 - Dech, Silas A1 - Schaefer, Laura T1 - How to confuse motor control BT - passive muscle shortening after contraction in lengthened position reduces the muscular holding stability in the sense of adaptive force JF - Life : open access journal N2 - Adaptation to external forces relies on a well-functioning proprioceptive system including muscle spindle afferents. Muscle length and tension control in reaction to external forces is most important regarding the Adaptive Force (AF). This study investigated the effect of different procedures, which are assumed to influence the function of muscle spindles, on the AF. Elbow flexors of 12 healthy participants (n = 19 limbs) were assessed by an objectified manual muscle test (MMT) with different procedures: regular MMT, MMT after precontraction (self-estimated 20% MVIC) in lengthened position with passive return to test position (CL), and MMT after CL with a second precontraction in test position (CL-CT). During regular MMTs, muscles maintained their length up to 99.7% +/- 1.0% of the maximal AF (AF(max)). After CL, muscles started to lengthen at 53.0% +/- 22.5% of AF(max). For CL-CT, muscles were again able to maintain the static position up to 98.3% +/- 5.5% of AF(max). AFiso(max) differed highly significantly between CL vs. CL-CT and regular MMT. CL was assumed to generate a slack of muscle spindles, which led to a substantial reduction of the holding capacity. This was immediately erased by a precontraction in the test position. The results substantiate that muscle spindle sensitivity seems to play an important role for neuromuscular functioning and musculoskeletal stability. KW - maximal isometric Adaptive Force KW - holding capacity KW - muscle stability KW - neuromuscular functioning KW - neuromuscular control KW - motor control KW - muscle spindle KW - muscle physiology KW - regulatory physiology Y1 - 2023 U6 - https://doi.org/10.3390/life13040911 SN - 2075-1729 VL - 13 IS - 4 PB - MDPI CY - Basel ER -