2012 Annual Conference

Lin, Suh-Jen

Physical Therapy Program, Texas Woman's University, Dallas, TX

This is an exploratory study with the aim to examine the relationships between physical activity and performance measures in individuals with lower-limb amputation. : For people with lower-limb amputation, the incidence of falls is higher than that of their counterparts. Literature shows that gait variability is related to falls. A higher physical activity level may be related to a better cardiovascular endurance and a lower risk of falls in people with amputation, then promoting physical activity would be an important strategy for them to improve health and reducing falls.  During comfortable walking, a person probably would not vary his/her step length a lot in order to minimize energy consumption, whereas the person would need to vary step width constantly to maintain balance during step-to-step perturbation. Performance measures included in the study are the Six-minute walk test, gait variability, comfortable walking speed.

Twenty individuals enrolled in the study (Age: 50 ±11 yrs, height: 175 ± 8 cm, Weight: 90 ±22 kg) with informed consents obtained. Twelve of them had transtibial amputation, seven had transfemoral amputation, and one had through-knee amputation.

Participants were recruited from metropolitan amputee support groups. Each participant performed a comfortable walking for 3 minutes followed by a six-minute walk test on a hallway. Physical activity was indicated by the average of 7-day step counts via a pedometer. Temporal-spatial gait parameters were collected via the GaitRite instrumented walkway during the comfortable walking. Gait variability was indicated by the coefficient of variation of each gait parameter.

Descriptive statistics was used for demographic data. Pearson correlation analysis was conducted between physical activity level and the following measures respectively: (1) comfortable walking speed, (2) six-minute walk distance, (3) step length variability, and (4) step width variability. Significance was set at 0.05.  

Physical activity had a good relationship to the comfortable walking speed (r = 0.76), the six-minute walk distance (r = 0.67), and an inverse relation to the step length variability of the prosthetic leg (r = - 0.46) and the sound leg (r = - 0.47), and a moderate relation to the step width variability (r = 0.44).

The results seemed to support our hypotheses that individuals with lower-limb amputation and a higher physical activity level would also have a better cardiovascular endurance, a faster comfortable walking speed, and a lower risk of falls. However, our conclusion is limited due to the small sample size.

Promotion of physical activity in people with lower-limb amputation is important. Innovative community-based health promotion programs for people with lower-limb amputation could be one of the new frontiers for future physical therapy practice.