Nonarticulated prostheses, or stubbies, used by people with bilateral transfemoral or through-knee amputations can be used exclusively or alongside full-length articulated prostheses. A team of researchers studying the implications of stubby prosthesis use on musculoskeletal function and movement patterns concluded that, when compared to those who used multiple prosthesis types, stubbies-only users presented signs of lower overall muscle volume.
The researchers collected gait data using a ten-camera motion capture system from two groups of four men with traumatic bilateral transfemoral amputations: one group exclusively used stubbies and the other used multiple prostheses, including stubbies and full-length articulated prostheses. Both cohorts completed level-ground walking trials wearing stubby prostheses. Muscle parameters were quantified through high-resolution magnetic resonance imaging scans.
Compared with the participants who used multiple prostheses, stubbies-only users showed lower walking speeds by 15 percent (0.79 versus 0.93 m/s), lower cadence by 20 percent (91.2 versus 114.7 steps/min), lower peak hip flexion angles by 45 percent (19.7 degrees versus 35.9 degrees), and larger peak-to-peak anterior pelvic tilt by 103 percent (15.8 degrees versus 7.8 percent).
The study’s authors concluded that the lower overall muscle volume of stubbies-only users may affect their current and future functional abilities.
The open-access study, “Biomechanical assessment of persons with bilateral transfemoral/through-knee amputations using stubby prostheses: A pilot study,” was published in Prosthetics & Orthotics International.
