Knee Crutch Impacts Vertical Ground Reaction Force During Walking Gait

Garrett Belding, Charles Marks, Christian Maron, Joshua Haworth AFFILIATION: Human Movement Science, Oakland University, Rochester, MI 48309Topical Category: 409 clinical biomechanics BACKGROUND: The hands-free knee crutch straps to the thigh and shank and includes a platform that supports the shank while providing vertical support under the knee through a post. This should afford bipedal gait similar to non-crutched walking. PURPOSE: Evaluate gait characteristics between no crutch (NC) and knee crutch (KC) conditions. METHODS: Participants (7 female, 3 male) walked across embedded ground-level force plates during separate NC and KC conditions, with the crutch on the dominant leg during the KC condition. Vertical ground reaction forces (VGRF) were measured during heel strike (HS) and toe-off (TO), and stance time was measured as the time from heel strike to toe-off (ST). Separate repeated measures ANOVA (condition x leg) were conducted for each measure, testing for main effects and interaction with alpha at .05. RESULTS: Summary measures for each condition are reported in Table 1. All ANOVA main and interaction effects were significant (p < .037), except the interaction between NC-KC x leg effect during TO. Table 1. - Mean ± SD of VGRF during HS and TO and stance time of the dominant (DM) and non-dominant (ND) legs during crutch (KC) and no-crutch (NC) trials. HS (Newtons, N) TO (Newtons, N) ST (milliseconds) Knee Crutch Crutched leg 465 ± 221 659 ± 97 890 ± 257 KC (ND) Non-dominant leg 717 ± 166 708 ± 124 1169 ± 235 No Crutch Dominant leg 731 ± 163 719 ± 126 773 ± 80 Non-dominant leg 722 ± 164 719 ± 124 759 ± 81 CONCLUSION: Though all participants were able to demonstrate comfortable bipedal gait, many significant differences were found in the VGRF between conditions. This indicates that healthcare providers may want to consider patient education when providing the KC option.