Citation

Sawers A, Bhatt T. J. Neurophysiol. 2018; 120(4): 1534-1546.

Affiliation

Physical Therapy, University of Illinois at Chicago, United States.

Copyright

(Copyright © 2018, American Physiological Society)

DOI

10.1152/jn.00286.2018

PMID

29995607

Abstract

Is there a neuromuscular basis for falls? If so it may provide new insight into falls, their assessment and treatment. We hypothesized that falls and recoveries from a laboratory-induced slip would be characterized by differences in multi-muscle coordination patterns. Using muscle synergy analysis we identified different multi-muscle coordination patterns between older adults who fell and those who recovered from a laboratory-induced "feet-forward" slip. Participants who fell recruited fewer muscle synergies than participants who recovered. This suggests that a fall may result from recruiting an inadequate number of muscle synergies to produce the necessary mechanical functions required to maintain balance. Participants who fell also recruited different muscle synergies, including one with high levels of co-activity consistent with a startle-like response. These differences in multi-muscle coordination between slip outcomes were not accompanied by differences in slip difficulty or gait kinematics prior to or during the slip response. The differences in neuromuscular control may therefore reflect differences in sensorimotor control rather than kinematic constraints imposed by the slip, or the musculoskeletal system. Further research is required to test the robustness of these results and their interpretation with respect to additional mechanical variables (e.g., joint torques, ground reaction forces), responses to other fall types (e.g., trips), and within rather than between individuals.

Language: en

Keywords

balance; falls; muscle coordination; muscle synergy; neuromechanics