Eight weeks of a lower limb resistance training protocol and gait performance in patients with symptomatic mild to moderate knee osteoarthritis

Background: The role of strengthening the lower limbs to optimize the biomechanics of the hip, knee and ankle during walking in patients with knee osteoarthritis, is still unclear. This study aimed to analyse the walking biomechanics of individuals with symptomatic mild to moderate knee osteoarthritis before and after a simplified lower limb resistance training protocol, focused on knee joint exercises with individualized load.

Methods: Forty-one patients with symptomatic and radiographic mild to moderate knee osteoarthritis underwent 3D gait analysis pre-post 8 weeks lower limb resistance training protocol performed 3 times a week. Parameters investigated were spatiotemporal, sagittal range of motion, flexion and extension minimum and maximum values, power and moment of hip, knee and ankle, as well as self-reported pain and physical function by the Western Ontario MacMaster University Osteoarthritis Index. Paired t test, Wilcoxon, Spearman's correlation and a logistic model were used for statistical analysis, with p < 0.05. Pain improvement more than 2 points was considered clinically relevant. The effect size (ES) was calculated using Cohen's d.

Results: Post protocol walking speed increased 6.7% (ES: 0.711), cadence 3.7% (ES: 0.655), stride length 2.6% (ES: 0.542), and double support time reduced 6.9% (ES:0.459). It was also observed a significant increase in one maximum repetition test for legpress 46%, knee extension 23% and knee flexion chair 27% (p < 0.001). Patients reported a 62.5% reduction in pain (ES:1.518) and 64.9% improvement in physical function (ES:1.376). 82% of the patients presented more than 2 points improvement in pain. No evidence of strong correlations between pain, strength gains and gait parameters were found.

Conclusions: There was a significant and clinical improvement of spatiotemporal gait parameters, pain, physical function, and strength after 8-week lower limb resistance training protocol. Patients who had a clinically relevant pain improvement presented better gait performance.