Kinematic analysis of males with transtibial amputation carrying military loads

Abstract

Abstract-The biomechanical responses to load carriage, a common task for dismounted troops, have been well studied in nondisabled individuals. However, with recent shifts in the rehabilitation and retention process of injured servicemembers, there remains a substantial need for understanding these responses in persons with lower-limb amputations. Temporalspatial and kinematic gait parameters were analyzed among 10 male servicemembers with unilateral transtibial amputation (TTA) and 10 uninjured male controls. Participants completed six treadmill walking trials in all combinations of two speeds (1.34 and 1.52 m/s) and three loads (none, 21.8, and 32.7 kg). Persons with TTA exhibited biomechanical compensations to carried loads that are comparable to those observed in uninjured individuals. However, several distinct gait changes appear to be unique to those with TTA, notably, increased dorsiflexion (deformation) of the prosthetic foot/ankle, less stance knee flexion on the prosthetic limb, and altered trunk forward lean/excursion. Such evidence supports the need for future work to assess the risk for overuse injuries with carried loads in this population in addition to guiding the development of adaptive prosthetic feet/components to meet the needs of redeployed servicemembers or veterans/civilians in physically demanding occupations.

Center of pressure and total force analyses for amputees walking with a backpack load over four surfaces

“…In this study, changes in MaxLat were only observed when walking up a ramp. Consistent with previous research on able-bodied participants (Birrell and Haslam, 2009;Castro et al, 2013;Harman et al, 2000;Simpson et al, 2012) and individuals with transtibial amputations (Doyle et al, 2014;Schnall et al, 2014), double support time increased when walking with a backpack. Participants in this study also walked slower when carrying a backpack, which typically increases double support time (Kirtley et al, 1985).…”

“…A common characteristic observed when walking with a backpack load is increased forward trunk lean (Attwells et al, 2006;Caron et al, 2013;Doyle et al, 2014;Polcyn et al, 2002;Schnall et al, 2014). A recent study examined the angle between the center of mass and the ankle and knee (referenced to vertical) and demonstrated that these angles did not change with increasing load (Caron et al, 2013).…”

“…Prosthetic limb knee and hip joint flexion increased during weight acceptance and greater prosthetic ankle dorsiflexion was found when walking with a backpack load (Doyle et al, 2014). Schnall et al (2014) reported individuals with transtibial amputation exhibited similar kinematic compensations as able-bodied when carrying loads, but individuals with a transtibial amputation had greater ankle dorsiflexion on the prosthetic limb and forward trunk lean/excursion. However, the amputee load carriage literature has focused on level ground walking.…”

“…Carrying a backpack load may magnify these compensations and increase the risk of injury (Knapik et al, 2012). Previous research demonstrated that individuals with transtibial amputations walking with a backpack load over level ground make similar temporal-spatial gait parameter alterations as able-bodied individuals (Doyle et al, 2014;Schnall et al, 2014). Prosthetic limb knee and hip joint flexion increased during weight acceptance and greater prosthetic ankle dorsiflexion was found when walking with a backpack load (Doyle et al, 2014).…”

Mechanical and dynamic characterization of prosthetic feet for high activity users during weighted and unweighted walking

“…Schnall et al [ 5 ] found that compared to able-bodied individuals, lower-limb prosthesis users exhibit greater metabolic costs while walking with added loads, both at mid-range and high-end speeds of military foot marches. Other studies have shown that during weighted walking, lower-limb prosthesis users exhibit greater (and asymmetrical) demands on the musculoskeletal system [ 6 ] and larger deflections of the prosthetic ankle-foot system compared to unweighted walking [ 7 , 8 ]. The latter, in particular, suggests additional work focused specifically on the functional implications of these load responses is warranted.…”