A torsion adaptor is a prosthetic component that can increase transverse plane compliance of a transtibial prosthesis and decrease the torque applied to the residual limb, but whether this would lead to improvements in patients’ mobility, pain, and fatigue was not known. To this extent, a team from the U.S. Veterans Affairs (VA) Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Seattle, Washington, studied the benefits individuals with transtibial amputations experience when using a torsion adaptor. The study was published online in the April issue of Clinical Orthopaedics and Related Research.
Ten individuals with unilateral transtibial amputations used a torsion or rigid adaptor in random order. Functional mobility was assessed through a field measurement using an activity monitor and through a laboratory measurement using a six-minute walk test that included turns. The residual limb pain grade was used to assess self-perceived pain, and the Multidimensional Fatigue Inventory was used to assess fatigue. The researchers found relatively small functional differences for subjects who used a torsion adaptor versus a rigid adaptor. When using a torsion adaptor, subjects tended to take more low- and medium-intensity steps per day, and they also experienced less pain interference with activities. However, patients took a similar number of total steps per day, walked a comparable distance in six minutes, and reported similar residual limb pain and fatigue whether using a torsion or rigid adaptor.
For a moderately active group of amputees, the torsion adapter did not translate to substantial improvements in functional mobility and self-perceived pain and fatigue. The small increases in low- and medium-intensity activities with less pain interference when wearing a torsion adaptor provides evidence to support prescribing this device for individuals with amputations who have difficulty navigating the household and community environments.