A Pilot Study on Whether Cycling with Different Levels of Electronic Assistance Changes Muscle Activity of the Lower Limb in People with Knee Osteoarthritis

Background: Knee osteoarthritis (KOA) often results in reduced physical activity. This exploratory study evaluated lower limb muscle activity across three e-cycling assistance levels and examined e-cycling’s influence on kinesiophobia, stress and exercise motivation in individuals with KOA. Methods: Ten participants cycled with no, low and high assistance on an e-bike. Muscle activity and knee kinematics were measured using surface electromyography and inertia measurement units. A subset of four participants completed questionnaires assessing kinesiophobia (TSK-17), perceived stress (PSS), and exercise motivation (BREQ-3). Muscle activity across the three levels of assistance was analysed using a linear mixed-effects model. Results: Peak and mean muscle activity of rectus femoris (p = 0.01; 0.039), vastus medialis oblique (p = 0.0002; 0.001) and biceps femoris (p = 0.002; 0.03) were lower during high-assistance compared to the no-assistance cycling. No significant differences were observed in mean muscle activity between no- and low-assistance cycling. Reported exertion and pain were low during e-cycling, with kinesiophobia (M = 35.8 ± 2.5 to 33.3 ± 3.5) decreasing following e-cycling, whereas perceived stress (M = 14 ± 5.7 to 14.5 ± 3.3) increased marginally in our small sample. In the small subgroup of participants, the Behaviour Regulation Exercise Questionnaire outcomes increased in four out of six subscores post-exercise. Conclusions: Considering the differences in muscle activity recorded, and given that this is a pilot study, we propose that e-cycling may be an ideal way of introducing graded exercise to KOA patients, potentially allowing them to maintain physical activity and self-management of their disease.