Real-time visual feedback affects peak propulsive horizontal force and metabolic cost in individuals with unilateral transtibial amputation during walking.

The BiOM powered prosthesis increased affected leg peak propulsive hGRF compared with the ESAR prosthesis.

• Affected leg (AL) peak propulsive hGRF increased by 0.014–0.017 body weight (BW) when participants used the BiOM compared with the ESAR prosthesis.
• Twelve participants with unilateral transtibial amputation walked at 1.25 m/s during testing.
• Both ESAR and BiOM conditions were tested with and without visual feedback of peak propulsive hGRF.

The BiOM powered prosthesis decreased peak propulsive hGRF asymmetry compared with the ESAR prosthesis.

• Peak propulsive hGRF asymmetry decreased by 9.4–16.3 percentage points when participants used the BiOM compared with the ESAR prosthesis.
• Individuals with unilateral transtibial amputation using a passive-elastic ESAR prosthesis have asymmetrical peak propulsive hGRF compared with nonamputees.
• Twelve participants with uTTA were tested walking at 1.25 m/s.

The BiOM powered prosthesis reduced net metabolic power compared with the ESAR prosthesis.

• Net metabolic power decreased by 0.16–0.26 W/kg when participants used the BiOM compared with the ESAR prosthesis.
• Twelve participants with uTTA walked at 1.25 m/s under both prosthesis conditions.
• Individuals with uTTA experience a greater metabolic cost of walking compared with nonamputees, which motivated the comparison.

Visual feedback of peak propulsive hGRF increased affected leg peak propulsive hGRF and decreased peak propulsive hGRF asymmetry.

• When provided with visual feedback, participants increased AL peak propulsive hGRF regardless of prosthesis type (ESAR or BiOM).
• Visual feedback also decreased peak propulsive hGRF asymmetry when using either prosthesis.
• Feedback was provided in real time during walking at 1.25 m/s across 12 participants with uTTA.

Visual feedback of peak propulsive hGRF incurred a greater metabolic cost regardless of prosthesis type.

• Participants incurred a greater metabolic cost when given visual feedback of peak propulsive hGRF when using either the ESAR or BiOM prosthesis.
• This finding held despite simultaneous improvements in AL peak propulsive hGRF and asymmetry with feedback.
• The authors suggest future device designs should explore biofeedback and device control to help individuals more effectively use a powered prosthesis.

Individuals with unilateral transtibial amputation using a passive-elastic ESAR prosthesis exhibit asymmetrical peak propulsive hGRF and greater metabolic cost of walking compared with nonamputees.

• Asymmetrical peak propulsive hGRF is a characteristic gait feature in this population using ESAR prostheses.
• Greater metabolic cost of walking and greater risk of developing secondary comorbidities are noted compared with nonamputees.
• These characteristics motivated investigation of both powered prosthesis use and biofeedback as potential interventions.