Balance control deficits in individuals with a transtibial amputation with and without visual input

Background: Many individuals with a transtibial amputation (TTA) exhibit balance deficits after limb loss. However, limited evidence exists on balance deficits of individuals with a TTA using hip, knee, and ankle kinematics and center of mass outcomes.

Objectives: To identify balance control deficits in individuals with a TTA and determine to what extent they are accentuated without visual inputs.

Study design: Cross-sectional.

Methods: Ten individuals with TTA and 10 healthy controls undertook a biomechanical assessment during a 30-s quiet standing task with eyes open (EO) and eyes closed (EC). The mean trunk, hip, knee, and ankle angles and center of pressure (COP) and center of mass excursions were calculated.

Results: More ankle dorsiflexion was observed for amputated limbs compared with intact lower limbs (mean difference: 5.8-degree, P = 0.031). Less anteroposterior (mean difference: 26.5 mm, P < 0.001) and mediolateral (ML) (mean difference: 4.2 mm, P = 0.042) COP excursions were found for amputated limbs compared with intact lower limbs and for control limbs compared with intact limbs (mean difference: 18.8 mm, P = 0.019). Greater ML COP excursion was found during EC than during EO condition (mean difference: 1.1 mm, P = 0.037).

Conclusions: Individuals with a TTA presented a greater reliance on the intact lower limb, as highlighted by the greater ankle plantarflexion and anteroposterior and ML COP excursions for intact limbs compared with amputated limbs during quiet standing tasks. During EC condition, both groups exhibited greater ML COP excursions compared with EO condition, suggesting less postural stability. These differences may place them at greater risk of falling.