Patients with unilateral dysvascular transtibial amputation (TTA) adopt movement compensations that are required to maintain balance and achieve ambulation in the absence of ankle plantar flexion, and result in increased and asymmetric joint loading patterns. As a result, this population is at an increased risk of overuse injuries, such as low back pain (LBP). Clinical gait analysis is used to guide diagnostics in movement retraining following amputation, and is performed using instrumented (research based) or observational analyses (clinically based). However, instrumented analyses are currently impractical in most clinical settings due to expense and computational limitations. This dissertation presents the use of segmental angular momentum to describe movement compensations in patients with TTA, and assess their effects on the musculoskeletal system; which provides a potential platform applicable in both instrumented and observational settings.
Ten patients with unilateral dysvascular TTA and two cohorts (patients with diabetes mellitus and healthy controls) completed one experimental study in which whole-body kinematics and core muscle demand were collected during walking and bilateral stepping tasks. Specific Aim 1 described the foundations of the separation of angular momentum into two components, translational (TAM) and rotational angular momentum (RAM) to describe movement coordination during healthy walking. Euler’s rotational laws were used to calculate segmental translational and rotational moments, which provide insight into the effort required to generate and arrest momentum by their relation to external forces and moments. Specific Aim 2 described trunk and pelvis movement compensations in patients with TTA during walking using TAM and RAM. Specific Aim 3 described the trunk translational and rotational moments in patients with TTA during step ambulation. Finally, Specific Aim 4 described the demand from the core musculature that supports trunk movement compensations in patients with TTA during step ambulation.
The results from these Specific Aims indicate that patients with TTA generate larger amounts of TAM and RAM, which were caused by larger translational and rotational trunk moments and demand from core muscles, than healthy controls. These compensations alter the low back loading patterns, which may be reduced by targeted strengthening and retraining motor control compensations to better support trunk movements.