Aberrations in the control of quadriceps muscle force in patients with knee osteoarthritis

Abstract

Objective. To characterize the distribution of error in knee joint proprioception, quadriceps force accuracy and steadiness, and muscle strength in patients with knee osteoarthritis (OA). Special attention was paid to eccentric strength. Methods. We compared knee OA patients (n ‫؍‬ 20: 15 women, 5 men) with age-and sex-matched, symptom-free adults. Knee pain and mobility were assessed with standard tests. Knee joint proprioception was measured with a repositioning test. Quadriceps force accuracy and steadiness were determined during a force target-tracking task. Maximal voluntary quadriceps force was measured during eccentric, isometric, and concentric contractions. Results. OA patients had knee pain, needed 67% more time to complete 4 functional tasks, and produced 82% more proprioception errors (all P < 0.05). About 80% of this error was due to overshooting the target and 68% of the overshooting error occurred at 2 of the 5 least flexed knee joint positions. OA patients had 89% more errors in accurately matching target forces during submaximal quadriceps contractions and in the same tasks, OA patients also produced these forces with 155% more variability (all P < 0.05). OA patients had especially weakened ability to produce maximal voluntary eccentric strength. Conclusion. Quadriceps dysfunction in knee OA includes impaired proprioception, especially in the more extended knee joint positions; impaired ability to accurately and steadily control submaximal force; and impaired eccentric strength. These results have implications for designing exercise and rehabilitation programs for patients with knee OA.

Knee extensor torque of men with early degrees of osteoarthritis is associated with pain, stiffness and function

“…Therefore, the strength deficits in this muscle can compromise its role in absorbing loads 1,12 . Considering that individuals with knee OA usually present weakness of the quadriceps muscle, we suggest that these patients experience increased joint loading, which could contribute to increased pain.…”

“…After receiving the test instructions, the subjects performed five maximal concentric and eccentric isokinetic contractions with a range of motion from 20° to 90° (being 0 degrees meaning full knee extension). The rest between each type of contraction was of 5 minutes duration 12 . Prior to each assessment, the subjects performed three submaximal contractions to familiarize themselves with the procedure.…”

“…Generally, studies have evaluated patients with advanced OA 12,13 or have included patients with mild, moderate and severe OA in the same study group 14,15 , making it impossible to extrapolate the results to populations in the early stages of OA. Thus, a study evaluating the relationship between the strength of the quadriceps muscle and the symptoms experienced by individuals with early stages of knee OA is relevant, especially with regards to the design of rehabilitation programs.…”

Experimental muscle pain increases normalized variability of multidirectional forces during isometric contractions

“…Increased variability of force and movement have been associated with the development of musculoskeletal disorders and pain (Madeleine 2010), such as knee osteoarthritis and subacromial impingement syndrome (Hortobágyi et al 2004;Bandholm et al 2006). Multiple neuromuscular mechanisms could be responsible for the pain-induced increase in force fluctuations.…”

“…Increased force variability has been associated with muscle fatigue (Missenard et al 2009), ageing (Tracy 2007), increased risk of falls (Carville et al 2007), and in particular, higher force fluctuations were observed in patients with chronic musculoskeletal pain disorders such as knee osteoarthritis and subacromial impingement syndrome compared with healthy controls (Hortobágyi et al 2004;Bandholm et al 2006). Although it has been shown that pain may cause changes in muscle coordination (Graven-Nielsen et al 1997), it is still unclear how these changes affect the three-directional distribution of force variability.…”