TY - JOUR

T1 - The role of load-dependent sensory input in the control of balance during gait in rats

AU - Popov, Alexander

AU - Lyakhovetskii, Vsevolod

AU - Bazhenova, Elena

AU - Gorskii, Oleg

AU - Kalinina, Daria

AU - Merkulyeva, Natalia

AU - Musienko, Pavel

N1 - Publisher Copyright: © 2021.

PY - 2021/8/1

Y1 - 2021/8/1

N2 - Locomotor activity requires fine balance control that strongly depends on the afferent input from the load receptors. Following hindlimb unloading (HU), the kinematic and EMG activity of the hindlimbs is known to change significantly. However, the effects of HU on the integrative control mechanisms of posture and locomotion are not clear. The goal of the present study was to evaluate the center of mass (CoM) dynamic stabilization and associated adaptive changes in the trunk and hindlimb muscle activity during locomotion after 7 days of HU. The EMG signals from the muscles of the low lumbar trunk [m. longissimus dorsi (VERT)] and the hind limb [m. tibialis anterior (TA), m. semitendinosus (ST), m. soleus (SOL)] were recorded together with the hindquarter kinematics during locomotion on a treadmill in six rats before and after HU. The CoM lateral shift in the step cycle significantly increased after HU and coincided with the enhanced activity of the VERT. The mean EMG of the TA and the ST flexor activity increased significantly with reduction of their burst duration. These data demonstrate the disturbances of body balance after HU that can influence the basic parameters of locomotor activity. The load-dependent mechanisms resulted in compensatory adjustments of flexor activity toward a faster gait strategy, such as a trot or gallop, which presumably have supraspinal origin. The neuronal underpinnings of these integrative posture and locomotion mechanisms and their possible reorganization after HU are discussed.

AB - Locomotor activity requires fine balance control that strongly depends on the afferent input from the load receptors. Following hindlimb unloading (HU), the kinematic and EMG activity of the hindlimbs is known to change significantly. However, the effects of HU on the integrative control mechanisms of posture and locomotion are not clear. The goal of the present study was to evaluate the center of mass (CoM) dynamic stabilization and associated adaptive changes in the trunk and hindlimb muscle activity during locomotion after 7 days of HU. The EMG signals from the muscles of the low lumbar trunk [m. longissimus dorsi (VERT)] and the hind limb [m. tibialis anterior (TA), m. semitendinosus (ST), m. soleus (SOL)] were recorded together with the hindquarter kinematics during locomotion on a treadmill in six rats before and after HU. The CoM lateral shift in the step cycle significantly increased after HU and coincided with the enhanced activity of the VERT. The mean EMG of the TA and the ST flexor activity increased significantly with reduction of their burst duration. These data demonstrate the disturbances of body balance after HU that can influence the basic parameters of locomotor activity. The load-dependent mechanisms resulted in compensatory adjustments of flexor activity toward a faster gait strategy, such as a trot or gallop, which presumably have supraspinal origin. The neuronal underpinnings of these integrative posture and locomotion mechanisms and their possible reorganization after HU are discussed.

KW - Evolution of the sensorimotor system

KW - Hindlimb unloading

KW - Load-dependent afferent input

KW - Locomotion

KW - Posture

KW - Rat

KW - Sensory feedback

KW - Hindlimb

KW - Gait

KW - Rats

KW - Animals

KW - Electromyography

KW - Muscle, Skeletal

KW - HINDLIMB MUSCLES

KW - WALKING

KW - EPAXIAL MUSCLE FUNCTION

KW - ELECTROMYOGRAPHIC ANALYSIS

KW - INTERLIMB COORDINATION

KW - FUNCTIONAL-ROLE

KW - MOTOR PATTERNS

KW - ANKLE EXTENSOR MUSCLES

KW - TREADMILL LOCOMOTION

KW - CAT HINDLIMB

UR - http://www.scopus.com/inward/record.url?scp=85110255228&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/0a1d72d5-87b7-389b-95ad-4747fd4d0baa/

U2 - 10.1242/jeb.242138

DO - 10.1242/jeb.242138

M3 - Article

C2 - 34350950

AN - SCOPUS:85110255228

VL - 224

JO - Journal of Experimental Biology

JF - Journal of Experimental Biology

SN - 0022-0949

IS - 15

M1 - 242138

ER -