Understanding patient preference in prosthetic ankle stiffness.

Area of Science:

• Biomechanics
• Prosthetics and Orthotics
• Human Movement Science

Background:

• User preference is key for designing, controlling, and prescribing prostheses.
• Understanding the physiological drivers and clinical benefits of prosthetic preference is crucial.

Purpose of the Study:

• To investigate the physiological factors influencing prosthetic ankle preference in individuals with below-knee amputation.
• To determine if preferred prosthetic ankle stiffness is associated with clinical benefits such as improved gait symmetry and metabolic efficiency.

Main Methods:

• Participants with unilateral below-knee amputation walked using a custom variable-stiffness prosthetic ankle.
• Subjects adjusted ankle stiffness via a dial at three walking speeds to find their preferred setting.
• Anthropomorphic, metabolic, biomechanical, and performance metrics were assessed around the preferred stiffness.

Main Results:

• Preferred prosthetic ankle stiffness was lower at self-selected treadmill speeds.
• Overground walking speed increased with ankle stiffness at or above the preferred level.
• Preferred stiffness maximized kinematic symmetry between prosthetic and intact limbs but did not correlate with body mass or metabolic rate.

Conclusions:

• Physiological factors significantly influence preferred prosthetic ankle stiffness.
• Prosthetic ankle preference may lead to clinically relevant improvements in gait parameters.
• Further research is warranted to fully elucidate the relationship between preference and clinical outcomes.