TY  - JOUR
A1  - Bittmann, Frank
A1  - Dech, Silas
A1  - Schaefer, Laura
T1  - Another way to confuse motor control
T2  - 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
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/64249
SN  - 2076-3425
VL  - 13
IS  - 7
PB  - MDPI
CY  - Basel
ER  -