@article{SchaeferDechBittmann2021,
  author    = {Schaefer, Laura and Dech, Silas and Bittmann, Frank},
  title     = {Adaptive force and emotionally related imaginations},
  series = {Heliyon},
  volume    = {7},
  journal   = {Heliyon},
  number    = {8},
  publisher = {Elsevier},
  address   = {London},
  issn      = {2405-8440},
  doi       = {10.1016/j.heliyon.2021.e07827},
  pages     = {13},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{BittmannDechSchaefer2023,
  author    = {Bittmann, Frank and Dech, Silas and Schaefer, Laura},
  title     = {Another way to confuse motor control},
  series = {Brain Sciences},
  volume    = {13},
  journal   = {Brain Sciences},
  number    = {7},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3425},
  doi       = {10.3390/brainsci13071105},
  pages     = {20},
  year      = {2023},
  abstract  = {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.},
  language  = {en}
}
@misc{DechBittmannSchaefer2021,
  author    = {Dech, Silas and Bittmann, Frank and Schaefer, Laura},
  title     = {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},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {710},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-51095},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-510950},
  pages     = {25},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{DechBittmannSchaefer2021,
  author    = {Dech, Silas and Bittmann, Frank and Schaefer, Laura},
  title     = {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},
  series = {Diagnostics : open access journal},
  volume    = {11},
  journal   = {Diagnostics : open access journal},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics11060923},
  pages     = {23},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@misc{DechBittmannSchaefer2020,
  author    = {Dech, Silas and Bittmann, Frank and Schaefer, Laura},
  title     = {Behavior of oxygen saturation and blood filling in the venous capillary system of the biceps brachii muscle during a fatiguing isometric action},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe 618},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe 618},
  number    = {618},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-46016},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-460166},
  pages     = {79 -- 87},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}
@article{DechBittmannSchaefer2020,
  author    = {Dech, Silas and Bittmann, Frank and Schaefer, Laura},
  title     = {Behavior of oxygen saturation and blood filling in the venous capillary system of the biceps brachii muscle during a fatiguing isometric action},
  series = {European Journal of Translational Myology},
  volume    = {30},
  journal   = {European Journal of Translational Myology},
  number    = {1},
  publisher = {Unipress},
  address   = {Padova},
  issn      = {2037-7460},
  doi       = {10.4081/ejtm.2019.8800},
  pages     = {79 -- 87},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}
@article{SchaeferDechAehleetal.2021,
  author    = {Schaefer, Laura and Dech, Silas and Aehle, Markus and Bittmann, Frank},
  title     = {Disgusting odours affect the characteristics of the adaptive force in contrast to neutral and pleasant odours},
  series = {Scientific Reports},
  volume    = {11},
  journal   = {Scientific Reports},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-021-95759-0},
  pages     = {1 -- 16},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@misc{SchaeferDechAehleetal.2021,
  author    = {Schaefer, Laura and Dech, Silas and Aehle, Markus and Bittmann, Frank},
  title     = {Disgusting odours affect the characteristics of the Adaptive Force in contrast to neutral and pleasant odours},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-54898},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-548980},
  pages     = {1 -- 16},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@misc{SchaeferDechWolffetal.2022,
  author    = {Schaefer, Laura and Dech, Silas and Wolff, Lara Luisa and Bittmann, Frank},
  title     = {Emotional Imagery Influences the Adaptive Force in Young Women},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {816},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-58201},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-582014},
  pages     = {23},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}
@article{SchaeferDechWolffetal.2022,
  author    = {Schaefer, Laura and Dech, Silas and Wolff, Lara Luisa and Bittmann, Frank},
  title     = {Emotional Imagery Influences the Adaptive Force in Young Women},
  series = {Brain Sciences},
  volume    = {12},
  journal   = {Brain Sciences},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel, Schweiz},
  issn      = {2076-3425},
  doi       = {10.3390/brainsci12101318},
  pages     = {23},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}