The functional evaluation criteria of musculoskeletal ambulation disability symptom (MADS) complex include the one-leg standing duration with eyes open and 3-m timed up and go test, but actual measurement is physically difficult for many patients. Thus, it is necessary to investigate a new, safe, and simple evaluation method. Considering that falls are likely to occur when one is stepping over an obstacle, we investigated the association between the musculoskeletal ambulation disability symptom complex and dynamic motions by dynamic motion analysis of “step-over” in healthy subjects and patients with the complex.

This study examined the association between the musculoskeletal ambulation disability symptom complex (MADS) and dynamic motions by performing dynamic motion analysis of “stepping over obstacles”, involving 11 MADS patients (group-M) compared to 10 young (-Y) and 11 elderly (-E) individuals with no health-related problems. All participants stepped over an obstacle with a height of 9cm by adopting 2 patterns: watching or not watching the obstacle on measurement of each joint angle and toe-obstacle clearance. The obtained values were examined through principal component analysis.

The age, experience of falls, and hip and knee joint angles showed higher absolute values representing factor loading on the first principal component, and this was consistent with the subsequent result of dynamic motion analysis focusing on joint angles: elderly group-E or M members showed greater hip and knee flexion to improve their toe-obstacle clearance. Therefore, the first principal component was considered to accurately represent the characteristics of the elderly, while the second principle component was likely to represent the characteristics of physical factors and clearance level.

It was clarified that items can be selected by dynamic motion analysis and principle component analysis, which may lead early evaluation of the musculoskeletal ambulation disability symptom complex.