This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Background Previous investigations on valgus knee bracing have mostly used the external knee adduction moment. This is a critical limitation, as the external knee adduction moment does not account for muscle forces that contribute substantially to the medial tibiofemoral contact force (MTCF) during walking. The aims of this pilot study were to: 1) determine the effect of a valgus knee brace on MTCF; 2) determine whether the effect is more pronounced after 8 weeks of brace use; 3) assess the feasibility of an 8-week brace intervention. Methods Participants with medial radiographic knee OA and varus malalignment were fitted with an Össur Unloader One© brace. Participants were instructed to wear the brace for 8 weeks. The MTCF was estimated via an electromyogram-assisted neuromuscular model with and without the knee brace at week 0 and week 8. Feasibility outcomes included change in symptoms, quality of life, confidence, acceptability, adherence and adverse events. Results Of the 30 (60% male) participants enrolled, 28 (93%) completed 8-week outcome assessments. There was a main effect of the brace (p<0.001) on peak MTCF and MTCF impulse, but no main effect for time (week 0 and week 8, p = 0.10), and no interaction between brace and time (p = 0.62). Wearing the brace during walking significantly reduced the peak MTCF (-0.05 BW 95%CI [-0.10, -0.01]) and MTCF impulse (-0.07 BW.s 95%CI [-0.09, -0.05]). Symptoms and quality of life improved by clinically relevant magnitudes over the 8-week intervention. Items relating to confidence and acceptability were rated relatively highly. Participants wore the brace on average 6 hrs per day. Seventeen participants reported 30 minor adverse events over an 8-week period. Conclusion Although significant, reductions in the peak MTCF and MTCF while wearing the knee brace were small. No effect of time on MTCF was observed. Although there were numerous minor adverse events, feasibility outcomes were generally favourable. Trial registration Australian and New Zealand Clinical Trials Registry (12619000622101).
PurposeThis study aimed to test the hypothesis that common weight-bearing exercises generate higher lower-limb muscle forces but do not increase medial tibiofemoral contact force (MTCF) when compared with walking in people with medial knee osteoarthritis and varus malalignment.MethodsTwenty-eight participants 50 yr or older with medial knee osteoarthritis and varus malalignment were recruited from the community. Three-dimensional lower-body motion, ground reaction forces, and surface EMG from 12 lower-limb muscles were acquired during five squat, lunge, single-leg heel raise, and walking trials, performed at self-selected speeds. An EMG-informed neuromusculoskeletal model with subject-specific bone geometry was used to estimate muscle forces (N) and body weight (BW)–normalized MTCF. The peak forces for muscle groups (knee extensors, knee flexors, ankle plantar flexors, and hip abductors) and peak MTCF were compared with walking using a multivariate analysis of variance model.ResultsThere was a significant main effect (P < 0.001). Post hoc tests (mean difference (95% confidence intervals)) showed that, compared with walking, participants generated higher peak knee extensor and flexor forces during squatting (extensor: 902 N (576 to 1227 N), flexor: 192 N (9.39 to 375 N)) and lunging (extensor: 917 N (604 to 1231 N), flexor: 496 N (198 to 794 N)), and lower peak hip abductor force during squatting (−1975 N (−2841 to −1108 N)) and heel raises (−1217 N (−2131 to −303 N)). Compared with walking, MTCF was lower during squatting (−0.79 BW (−1.04 to −0.53 BW)) and heel raises (−0.27 BW (−0.50 to −0.04 BW)). No other significant differences were observed.ConclusionsParticipants generated higher peak knee flexor and extensor forces during squatting and lunging but did not increase peak MTCF compared with walking. Clinicians can use these findings to reassure themselves and patients that weight-bearing exercises in these positions do not adversely increase forces within the osteoarthritic joint compartment.
Objective To compare the effect of stable supportive to flat flexible walking shoes on medial tibiofemoral contact force (MTCF) in people with medial knee osteoarthritis and varus malalignment. Design This was a randomized cross-over study. Twenty-eight participants aged ≥50 years with medial knee osteoarthritis and varus malalignment were recruited from the community. Three-dimensional full-body motion, ground reaction forces and surface electromyograms from twelve lower-limb muscles were acquired during six speed-matched walking trials for flat flexible and stable supportive shoes, tested in random order. An electromyogram-informed neuromusculoskeletal model with subject-specific geometry estimated bodyweight (BW) normalized MTCF. Waveforms were analyzed using statistical parametric mapping with a repeated measures analysis of variance model. Peak MTCF, MTCF impulse and MTCF loading rates (discrete outcomes) were evaluated using a repeated measures multivariate analysis of variance model. Results Statistical parametric mapping showed lower MTCF in stable supportive compared to flat flexible shoes during 5–18% of stance phase (p = 0.001). For the discrete outcomes, peak MTCF and MTCF impulse were not different between the shoe styles. However, mean differences [95%CI] in loading impulse (-0.02 BW·s [-0.02, 0.01], p<0.001), mean loading rate (-1.42 BW·s-1 [-2.39, -0.45], p = 0.01) and max loading rate (-3.26 BW·s-1 [-5.94, -0.59], p = 0.02) indicated lower measure of loading in stable supportive shoes compared to flexible shoes. Conclusions Stable supportive shoes reduced MTCF during loading stance and reduced loading impulse/rates compared to flat flexible shoes and therefore may be more suitable in people with medial knee osteoarthritis and varus malalignment. Trial registration Australian and New Zealand Clinical Trials Registry (12619000622101).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.