Healthy older adults have insufficient hip range of motion and plantar flexor strength to walk like healthy young adults

Dennis E Anderson,Michael L Madigan

doi:10.1016/j.jbiomech.2013.12.024

Dennis E Anderson, Michael L Madigan

Open Access

https://doi.org/10.1016/j.jbiomech.2013.12.024

Copy DOI

Abstract

Limited plantar flexor strength and hip extension range of motion (ROM) in older adults are believed to underlie common age-related differences in gait. However, no studies of age-related differences in gait have quantified the percentage of strength and ROM used during gait. We examined peak hip angles, hip torques and plantar flexor torques, and corresponding estimates of functional capacity utilized (FCU), which we define as the percentage of available strength or joint ROM used, in 10 young and 10 older healthy adults walking under self-selected and controlled (slow and fast) conditions. Older adults walked with about 30% smaller hip extension angle, 28% larger hip flexion angle, 34% more hip extensor torque in the slow condition, and 12% less plantar flexor torque in the fast condition than young adults. Older adults had higher FCU than young adults for hip flexion angle (47% vs. 34%) and hip extensor torque (48% vs. 27%). FCUs for plantar flexor torque (both age groups) and hip extension angle (older adults in all conditions; young adults in self-selected gait) were not significantly <100%, and were higher than for other measures examined. Older adults lacked sufficient hip extension ROM to walk with a hip extension angle as large as that of young adults. Similarly, in the fast gait condition older adults lacked the strength to match the plantar flexor torque produced by young adults. This supports the hypothesis that hip extension ROM and plantar flexor strength are limiting factors in gait and contribute to age-related differences in gait.

Highlights

Reported age-related differences in gait may arise from physiological or neuromuscular limitations in older adults (McGibbon, 2003; Winter et al, 1990)
Hip extension torque was tested at a target angle of 68° of hip flexion (ROM limited to 56°, 60°, 60°, 60°, 62°, 62° and 65° respectively in seven participants), hip flexion torque was tested at a target angle of 15° of hip extension (ROM limited to 11° and 13° respectively in two participants), and plantar flexion torque was tested at a target angle of 26° of dorsiflexion (ROM limited to 23° in one participant)
Both age groups used a majority of their available plantar flexor strength and hip extension range of motion (ROM) during gait, significantly more than the available capacity used for other measures examined

Summary

Introduction

Reported age-related differences in gait may arise from physiological or neuromuscular limitations in older adults (McGibbon, 2003; Winter et al, 1990). Many studies have reported reduced plantar flexor kinetics (e.g. peak torque, power generation and work) in older adults during gait (DeVita and Hortobagyi, 2000; Judge et al, 1996; Kerrigan et al, 1998; Monaco et al, 2009; Riley et al, 2001; Silder et al, 2008; Winter et al, 1990), which could be caused by reduced plantar flexor strength. This study examines the percentage of available strength and hip joint ROM, which we term functional capacity utilized (FCU), used by healthy young and older adults in level walking, in order to gain insight into the limitations underlying age-related differences in gait

Objectives

Methods

Results

Conclusion