Changes to level ground transtibial amputee gait with a weighted backpack

Many occupations and hobbies require the use of a weighted pack. To date there has been limited backpack gait studies performed on the amputee population. It is important that we address this knowledge gap in order to further improve individual's quality of living through changes in rehabilitation, and prosthesis development.

The study population was ten male, unilateral, traumatic, K4-level (ability for prosthetic ambulation with high impact, stress, or energy levels), transtibial amputees. Ten walking trials were collected on level ground; five with a 24.5 kg backpack and five without a backpack. Temporal-spatial parameters and kinematic and kinetic peak values for the ankle, knee, hip, pelvis, and trunk were collected and analyzed for significant differences.

Temporal-spatial parameters incurred changes that were congruent with the literature on able bodied individuals. Pelvis speeds and range of motion decreased with the pack. Knee flexion during weight acceptance increased, and was supported on the intact limb by increased eccentric knee power during weight acceptance. Hip flexion on both limbs also increased during weight acceptance while wearing the backpack.

The backpack load can be accommodated by people at a K4 functional level for level ground walking. At the prosthetic limb, greater deformation was found at the foot-ankle and further increases in pack weight and higher impact tasks (i.e., jogging) could lead to decreased performance for some prosthetic feet. Gait training programs should focus on removing any gait asymmetries and increasing the strength of both the hip and knee flexors.