Global Muscle Coactivation of the Sound Limb in Gait of People with Transfemoral and Transtibial Amputation.

Antonella Tatarelli,Alessio Silvetti,Mariano Serrao,Alberto Ranavolo,Tiwana Varrecchia,Francesco Draicchio,Cristiano De Marchis,Silvia Conforto,Lorenzo Fiori

doi:10.3390/s20092543

Abstract

The aim of this study was to analyze the effect of the level of amputation and various prosthetic devices on the muscle activation of the sound limb in people with unilateral transfemoral and transtibial amputation. We calculated the global coactivation of 12 muscles using the time-varying multimuscle coactivation function method in 37 subjects with unilateral transfemoral amputation (10, 16, and 11 with mechanical, electronic, and bionic prostheses, respectively), 11 subjects with transtibial amputation, and 22 healthy subjects representing the control group. The results highlighted that people with amputation had a global coactivation temporal profile similar to that of healthy subjects. However, amputation increased the level of the simultaneous activation of many muscles during the loading response and push-off phases of the gait cycle and decreased it in the midstance and swing subphases. This increased coactivation probably plays a role in prosthetic gait asymmetry and energy consumption. Furthermore, people with amputation and wearing electronic prosthesis showed lower global coactivation when compared with people wearing mechanical and bionic prostheses. These findings suggest that the global lower limb coactivation behavior can be a useful tool to analyze the motor control strategies adopted and the ability to adapt to the prosthetic device.

Highlights

Lower limb amputation leads to significant neural reorganization within the central nervous system (CNS) mostly due to the loss of the sensorimotor function caused by amputation [1,2]
We used a time-varying (Figure 2A), with the lack of significant differences when compared with function that together allows the simultaneous study of the activationin ofthe many muscles and can provide the control, suggests that the global coactivation temporal profile in people with amputation is similar information on the global compensatory strategy adopted by people with amputation in the sound limb
We found a significantly increased Deviation phase (DP) in both people with transtibial amputation (TTA) and transfemoral amputation (TFA) when compared with controls, without any difference between them

Summary

Introduction

Lower limb amputation leads to significant neural reorganization within the central nervous system (CNS) mostly due to the loss of the sensorimotor function caused by amputation [1,2]. Kinematic, kinetic, and surface electromyography (sEMG) gait findings reflect the compensatory efforts developed by people with amputation to protect the soft tissues of the sound limb [4] and to deal with the new prosthetic limb condition [7]. These compensatory mechanisms in the sound limb consist of increasing muscle activation, spending more time on the ground [20,21,22], and developing a greater and longer force production [22,23,24]. Varrecchia et al [6] showed that people using the bionic prosthetic knee

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Discussion

Conclusion