Abstract
BACKGROUND: Transfemoral amputation results in increased fall risk in part through compromised postural control and greater between-limb asymmetry compared to people without amputation. Bone-anchored limbs (BAL) are a rising alternative to socket-type prostheses that may alter postural control. RESEARCH QUESTION: How do static and dynamic postural control and between-limb symmetry compare for people with unilateral transfemoral amputation using a socket-type prosthesis or a BAL? METHODS: Twenty-six people with transfemoral amputation (10 socket/16 BAL) were tested during quiet standing and overground walking trials. We compared two static postural control measures (between-limb weight support distribution and limb contribution to anteroposterior center of pressure movement while standing) and one dynamic postural control measure (peak mediolateral and anteroposterior inclination angle while walking) between groups. The Absolute Symmetry Index (ASI) quantified between-limb symmetry. We compared interactions and main effects of group and limb using mixed factorial ANOVAs, and ASI using independent t-tests or Mann-Whitney U tests. RESULTS: There were no between-group differences (p > 0.39) for static postural control measures. Dynamically, BAL users showed smaller frontal plane inclination angles during amputated limb stance period of walking (p < 0.01) and greater sagittal plane inclination angle symmetry (p = 0.02). SIGNIFICANCE: BAL users had greater dynamic, but not static, postural control compared to socket-type prosthesis users, emphasizing the importance of evaluating movement across multiple postural control domains. Coordinated clinical efforts to optimize prosthetic fit and alignment and implement interventions are important to improve postural control and dynamic stability and reduce fall risk for people with BAL implantation.