Trunk Postural Control During Unstable Sitting Does Not Explain Whole-Body Angular Momentum Control During Walking Among Individuals With Unilateral Lower Limb Amputation.

During walking, uninjured individuals maintain whole-body angular momentum (WBAM) within a narrow range. Individuals with lower limb amputation (LLA) have demonstrated larger WBAM ranges during walking relative to uninjured controls, suggesting disrupted WBAM control. Given that the trunk is a principal contributor to WBAM and trunk control may be altered after LLA, we related trunk postural control isolated during unstable sitting and WBAM control during walking across 9 individuals with unilateral transfemoral amputation, 24 individuals with unilateral transtibial amputation, and 16 uninjured controls. Linear regressions revealed weak relationships (R2 = .050-.350, P < .071), particularly in the sagittal and transverse planes, between trunk postural control measures and WBAM ranges. Trunk postural control measures during unstable sitting were larger among individuals with LLA versus uninjured controls (P < .029) but were not different between individuals with transtibial amputation versus transfemoral amputation. Similarly, WBAM ranges during walking were larger in all planes between individuals with LLA versus uninjured controls (P < .005), with individuals with transtibial amputation having larger ranges than individuals with transfemoral amputation in the sagittal (P < .001) and frontal (P = .006) but not the transverse (P = 1.000) planes. Our findings suggest that trunk postural control during unstable sitting does not explain differences in WBAM control during walking among individuals with versus without LLA, particularly in the sagittal and transverse planes.