TY - JOUR
T1 - How Does Lower Limb Respond to Unexpected Balance Perturbations? New Insights from Synchronized Human Kinetics, Kinematics, Muscle Electromyography (EMG) and Mechanomyography (MMG) Data
AU - Zhu, Tanglong
AU - Lyu, Peizhao
AU - Li, Shuai
AU - Tong, Cheuk Ying
AU - Ling, Yan To
AU - Ma, Zonghao
N1 - Funding Information:
Funding: This research was funded by Hong Kong Research Grants Council (RGC) Direct Allocation Grant—Funding Support to Small Projects, grant number P0036830; Research Institute for Smart Ageing, The Hong Kong Polytechnic University, grant number P0038945; The Hong Kong Polytechnic University, grant number P0034491; and Associated Money, The Hong Kong Polytechnic University, grant number G4Y56R006.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/6/18
Y1 - 2022/6/18
N2 - Making rapid and proper compensatory postural adjustments is vital to prevent falls and fall-related injuries. This study aimed to investigate how, especially how rapidly, the multiple lower-limb muscles and joints would respond to the unexpected standing balance perturbations. Unexpected waist-pull perturbations with small, medium and large magnitudes were delivered to twelve healthy young adults from the anterior, posterior, medial and lateral directions. Electromy-ographical (EMG) and mechanomyographical (MMG) responses of eight dominant-leg muscles (i.e., hip abductor/adductors, hip flexor/extensor, knee flexor/extensor, and ankle dorsi-flexor/plantarflexors) together with the lower-limb joint angle, moment, and power data were rec-orded. The onset latencies, time to peak, peak values, and/or rate of change of these signals were analyzed. Statistical analysis revealed that: (1) agonist muscles resisting the delivered perturbation had faster activation than the antagonist muscles; (2) ankle muscles showed the largest rate of activation among eight muscles following both anteroposterior and mediolateral perturbations; (3) lower-limb joint moments that complied with the perturbation had faster increase; and (4) larger perturbation magnitude tended to evoke a faster response in muscle activities, but not necessarily in joint kinetics/kinematics. These findings provided insights regarding the underlying mechanism and lower-limb muscle activities to maintain reactive standing balance in healthy young adults.
AB - Making rapid and proper compensatory postural adjustments is vital to prevent falls and fall-related injuries. This study aimed to investigate how, especially how rapidly, the multiple lower-limb muscles and joints would respond to the unexpected standing balance perturbations. Unexpected waist-pull perturbations with small, medium and large magnitudes were delivered to twelve healthy young adults from the anterior, posterior, medial and lateral directions. Electromy-ographical (EMG) and mechanomyographical (MMG) responses of eight dominant-leg muscles (i.e., hip abductor/adductors, hip flexor/extensor, knee flexor/extensor, and ankle dorsi-flexor/plantarflexors) together with the lower-limb joint angle, moment, and power data were rec-orded. The onset latencies, time to peak, peak values, and/or rate of change of these signals were analyzed. Statistical analysis revealed that: (1) agonist muscles resisting the delivered perturbation had faster activation than the antagonist muscles; (2) ankle muscles showed the largest rate of activation among eight muscles following both anteroposterior and mediolateral perturbations; (3) lower-limb joint moments that complied with the perturbation had faster increase; and (4) larger perturbation magnitude tended to evoke a faster response in muscle activities, but not necessarily in joint kinetics/kinematics. These findings provided insights regarding the underlying mechanism and lower-limb muscle activities to maintain reactive standing balance in healthy young adults.
KW - balance control
KW - balance perturbation
KW - compensatory postural adjustment (CPA)
KW - electromyography (EMG)
KW - mechanomyography (MMG)
KW - onset latency
KW - reactive balance response
KW - skeletal muscle
KW - time to peak
KW - waist-pulling perturbation
UR - http://www.scopus.com/inward/record.url?scp=85132628940&partnerID=8YFLogxK
U2 - 10.3390/bios12060430
DO - 10.3390/bios12060430
M3 - Journal article
SN - 2079-6374
VL - 12
JO - Biosensors
JF - Biosensors
IS - 6
M1 - 430
ER -