Assessment of muscular and kinematic asymmetry following a transtibial amputation

This pilot study aimed to investigate muscle activation and joint kinematic asymmetry in individuals with transtibial amputation (TTA). We explored the relationship between neuromuscular activity using surface electromyography (sEMG) and gait mechanics using Xsens Awinda-Movella inertial measurement technology. Christensen et al. (2021) investigated movement asymmetries in transtibial amputees, particularly during high-demand tasks like step ascent. They found significantly greater asymmetries in knee and ankle mechanics compared to healthy controls [1]. Surface EMG and IMUs were used to assess the rectus femoris and biceps femoris during functional mobility tasks, including the Timed Up and Go (TUG) test and the 2-Minute Walk Test (2MWT). On average, rectus femoris activity was 44 % lower in the amputated limb compared to the intact limb. Our results align with findings by Sarroca et al., who reported that quadriceps activation was up to 30% lower than in controls, particularly at higher walking speeds, suggesting muscular asymmetries, while hamstring activation remained relatively consistent [2]. Unlike current research suggesting hamstring activity is largely unaffected by transtibial amputation, our findings showed a 155.6% increase in hamstring activation on the amputated limb, indicating a substantial compensatory role during TUG test. Correlations suggest that increased muscle activation was often associated with greater kinematic asymmetry, implying compensatory mechanisms. While differences were noted across prosthetic foot types, the small sample size limited firm conclusions. This study offers early insights into gait asymmetry and compensatory strategies in TTA individuals, highlighting the need for further investigation.

[1] Christensen JC, Kline PW, Murray AM, Christiansen CL. Movement asymmetry during low and high demand mobility tasks after dysvascular transtibial amputation. Clin Biomech (Bristol). 2020;80:105102.

[2] Sarroca N, Luesma MJ, Valero J, Deus J, Casanova J, Lahoz M. Muscle Activation during Gait in Unilateral Transtibial Amputee Patients with Prosthesis: The Influence of the Insole Material Density. J Clin Med. 2021;10(14).