Proprioceptive Fatigue Adaptation in Osteoarthritis

Neuromotor Adaptation to Fatigue: Changes in Lower Extremity Proprioception in Patients With Osteoarthritis

This study aims to investigate the effects of fatigue induced by isokinetic exercise on passive and active joint position sense in postmenopausal women diagnosed with knee osteoarthritis (gonarthrosis). A healthy control group matched for age and sex will also be included for comparative analysis. Participants will undergo proprioceptive assessments before and after an isokinetic fatigue protocol. We hypothesize that (1) fatigue will impair both passive and active joint position sense in patients with gonarthrosis, (2) active joint position sense will be more affected than passive sense, and (3) the deterioration in proprioception will be greater in the gonarthrosis group compared to healthy controls.

Osteoarthritis, particularly knee osteoarthritis (gonarthrosis), is a progressive musculoskeletal disease that severely affects lower extremity functions. Proprioceptive impairments in these patients can lead to altered motor control, reduced movement accuracy, and increased risk of falls. Fatigue may exacerbate these impairments by affecting sensory feedback from muscle spindles and joint receptors, which is critical for joint stability and motor control. In postmenopausal women, hormonal changes further compound muscle weakness and joint instability, highlighting the clinical importance of understanding proprioceptive changes following fatigue.

This experimental study will involve two groups: postmenopausal women with gonarthrosis and age-matched healthy controls. Participants will undergo an isokinetic fatigue protocol followed by assessments of passive and active joint position sense being more vulnerable. Understanding these changes will contribute to developing rehabilitation strategies focusing on proprioception and fatigue management.

We expect that isokinetic fatigue will impair proprioception, with active joint position

Inclusion Criteria:

• Female, aged 50-65
• Postmenopausal
• Grade 2-3 knee osteoarthritis (Kellgren-Lawrence Scale) for OA group
• No lower extremity surgery in the last 6 months
• No neuromuscular or orthopedic condition affecting the lower extremities

Exclusion Criteria:

• Severe balance disorders or vestibular disease
• Bilateral knee prosthesis or severe osteoporosis
• Lower extremity musculoskeletal injury in the last 6 months