Changes to transtibial amputee gait with a weighted backpack on multiple surfaces.

BACKGROUND Modern prosthetic technology and rehabilitation practices have enabled people with lower extremity amputations to participate in almost all occupations and physical activities. Carrying backpack loads can be an essential component for many of these jobs and activities; however, amputee gait with backpack loads is poorly understood. This knowledge gap must be addressed in order to further improve an individual's quality of living through changes in rehabilitation programs and prosthesis development. METHODS Ten male, unilateral, K4-level (ability or potential for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress, or energy levels), transtibial amputees completed ten walking trials at a self-selected pace on simulated uneven ground, ramp ascent, and ramp descent. Five trials were with a 24.5 kg backpack load and five trials without. Temporal-spatial parameters and kinematic peak values for the ankle, knee, hip, pelvis, and trunk were collected and analyzed for differences between backpack conditions. FINDINGS Each surface had novel findings not found on the other surfaces. However differences in temporal-spatial parameters were congruent with the literature on able bodied individuals. Pelvis and trunk angular velocities decreased with the backpack. Hip flexion on both limbs increased during weight acceptance while wearing the backpack, a common adaptation seen in able-bodied individuals on level ground. INTERPRETATION A 24.5 kg backpack load can be accommodated by transtibial amputees at the K4 functional level. Future studies on load carriage and gait training programs should include incline and descent due to the increased difficulty. Rehabilitation programs should verify hip and knee flexor strength and work to reduce intact limb reliance.