Paul S Sung1. 1. Department of Physical Therapy, Motion Analysis Center, Herbert H. and Grace A. Dow College of Health Professions, Central Michigan University, Health Professions Building 1220, Mt. Pleasant, MI, 48859, United States. Electronic address: sung1p@cmich.edu.
Abstract
BACKGROUND: Older adults with low bone mineral density (BMD) may exhibit early markers for physical frailty; however, there is a lack of understanding of the dominant limb support patterns during walking. RESEARCH QUESTION: The purpose of this study was to investigate limb support times during walking in healthy older adults with low BMD. METHODS: Seventy-seven right limb dominant older adults (48 female subjects, 29 male subjects) participated in the study. Each participant's BMD (g/cm2) was measured by dual-energy x-ray absorptiometry (DEXA), and a motion capture system was utilized to measure temporal-spatial gait parameters (cadence, speed, stride length, and limb support times). The limb support times included initial double limb support (IDS), single limb support (SS), and terminal double limb support (TDS) in the stance phase. RESULTS: Those limb support times were significantly different (F = 44.28, p = 0.001) and demonstrated an interaction with dominance (F = 9.44, p = 0.003). In stance phase, the IDS was longer on the non-dominant limb (t = -3.07, p = 0.003); however, the TDS was significantly longer on the dominant limb (t = 3.07, p = 0.003). The stride length was longer on the dominant limb (t = 2.45, p = 0.02) and was positively associated with single limb support on the dominant limb (r = 0.34 p = 0.001) compared with the non-dominant limb (r = -0.29, p = 0.001). SIGNIFICANCE: This longer stride length and single limb loading pattern on the dominant limb could increase asymmetrical balance in the stance phase. The gait modification strategies used to increase stride length on the non-dominant limb may allow for more functional symmetrical gait. Further investigation of asymmetric limb support patterns and gait modification strategies might be needed to enhance functional gait performance.
BACKGROUND: Older adults with low bone mineral density (BMD) may exhibit early markers for physical frailty; however, there is a lack of understanding of the dominant limb support patterns during walking. RESEARCH QUESTION: The purpose of this study was to investigate limb support times during walking in healthy older adults with low BMD. METHODS: Seventy-seven right limb dominant older adults (48 female subjects, 29 male subjects) participated in the study. Each participant's BMD (g/cm2) was measured by dual-energy x-ray absorptiometry (DEXA), and a motion capture system was utilized to measure temporal-spatial gait parameters (cadence, speed, stride length, and limb support times). The limb support times included initial double limb support (IDS), single limb support (SS), and terminal double limb support (TDS) in the stance phase. RESULTS: Those limb support times were significantly different (F = 44.28, p = 0.001) and demonstrated an interaction with dominance (F = 9.44, p = 0.003). In stance phase, the IDS was longer on the non-dominant limb (t = -3.07, p = 0.003); however, the TDS was significantly longer on the dominant limb (t = 3.07, p = 0.003). The stride length was longer on the dominant limb (t = 2.45, p = 0.02) and was positively associated with single limb support on the dominant limb (r = 0.34 p = 0.001) compared with the non-dominant limb (r = -0.29, p = 0.001). SIGNIFICANCE: This longer stride length and single limb loading pattern on the dominant limb could increase asymmetrical balance in the stance phase. The gait modification strategies used to increase stride length on the non-dominant limb may allow for more functional symmetrical gait. Further investigation of asymmetric limb support patterns and gait modification strategies might be needed to enhance functional gait performance.