Biomechanical Compensations May Lead to Secondary Pain After Transtibial Amputation
A study published online August 27 in Clinical Biomechanics measured the biomechanical compensations of the trunk and lower limbs during high-demand tasks such as step ascent and descent by identifying low back, hip, and knee joint moment patterns unique to people with transtibial amputations.
After a transtibial amputation, people experience movement compensations that are likely influenced by trunk posture and movement. The research study was conducted to further identify the compensations that are made during stepping tasks.
Kinematic and kinetic data were collected during step ascent and descent tasks from three groups: people with diabetes and a transtibial amputation, people with diabetes, and those who were healthy. An analysis of covariance (ANCOVA) was used to compare peak trunk, hip, and knee joint angles and moments in the sagittal and frontal planes between groups. Paired t-tests were used to compare peak joint angles and moments between amputated and intact limbs of the diabetic/transtibial amputation group.
The researchers found that during step ascent and descent, the people who had a transtibial amputation exhibited greater trunk forward flexion and lateral flexion compared to the other two groups, which resulted in greater low back moments and asymmetric loading patterns in the joints of the lower limb. The diabetic group exhibited similar knee joint loading patterns compared to the amputation group during step descent. According to the study's authors, the results suggest that some movement compensations may be confounded by the presence of diabetes and precede limb amputation. The increased and asymmetrical loading patterns identified may predispose individuals with transtibial amputation to the development of secondary pain conditions, such as low back pain or osteoarthritis.