Increased trunk flexion may underlie elevated knee flexor activity in people with knee osteoarthritis

Preece, SJ; Alghamdi, W

Abstract

Background: Previous research has demonstrated elevated activation of the knee flexor muscles in people with knee osteoarthritis. People with this condition have also been observed to walk with increased trunk flexion; this may alter biomechanical loading patterns and change muscle activation profiles. Therefore, the aim of this study was to understand the biomechanical effect of increasing trunk flexion during walking.
Methods: Kinetic and EMG data were collected from a sample of 20 people with knee osteoarthritis and a sample of 20 healthy matched controls during normal walking. Using a biofeedback protocol, participants were subsequently instructed to walk with a 5° increase in trunk flexion. Sagittal moments, muscle activations and co-contractions were then compared across a window in early stance with a two-way ANOVA test.
Results: When trunk flexion was increased, there was a corresponding increase in activity of the medial and lateral hamstrings and gastrocnemius muscles as well as a rise in medial co-contraction. This effect was consistent across the two groups. The most pronounced effect was observed for semitendinosus, which showed a dramatic change in activation profile in the healthy group and a 127% increase in activation during early stance.
Conclusions: This is the first study to demonstrate that increased trunk flexion in people with knee osteoarthritis may explain, to some degree, the elevated knee flexor activity and medial co-contraction which is associated with this disease. These findings motivate further work to understand the therapeutic potential of interventions designed to improve postural alignment

Citation

Preece, S., & Alghamdi, W. (2021). Increased trunk flexion may underlie elevated knee flexor activity in people with knee osteoarthritis. ˜The œKnee (Amsterdam. Online), 33, 216-225. https://doi.org/10.1016/j.knee.2021.10.006

• Journal Article Type: Article
• Acceptance Date: Oct 3, 2021
• Online Publication Date: Oct 27, 2021
• Publication Date: Dec 1, 2021
• Deposit Date: Dec 9, 2021
• Publicly Available Date: Oct 27, 2022
• Journal: The Knee
• Print ISSN: 0968-0160
• Publisher: Elsevier
• Volume: 33
• Pages: 216-225
• DOI: https://doi.org/10.1016/j.knee.2021.10.006
• Publisher URL: https://doi.org/10.1016/j.knee.2021.10.006
• Related Public URLs: http://www.elsevier.com/wps/product/cws_home/30449/description