Vastus medialis motor unit properties in knee osteoarthritis
نویسندگان
چکیده
BACKGROUND Maximal isometric quadriceps strength deficits have been widely reported in studies of knee osteoarthritis (OA), however little is known about the effect of osteoarthritis knee pain on submaximal quadriceps neuromuscular function. The purpose of this study was to measure vastus medialis motor unit (MU) properties in participants with knee OA, during submaximal isometric contractions. METHODS Vastus medialis motor unit potential (MUP) parameters were assessed in 8 patients with knee OA and 8 healthy, sex and age-matched controls during submaximal isometric contractions (20% of maximum isometric torque). Unpaired t-tests were used to compare groups for demographic and muscle parameters. RESULTS Maximum knee extension torque was ~22% lower in the OA group, a difference that was not statistically significantly (p = 0.11). During submaximal contractions, size related parameters of the needle MUPs (e.g. negative peak duration and amplitude-to-area ratio) were greater in the OA group (p < 0.05), with a rightward shift in the frequency distribution of surface MUP negative peak amplitude. MUP firing rates were significantly lower in the OA group (p < 0.05). CONCLUSIONS Changes in MU recruitment and rate coding strategies in OA may reflect a chronic reinnervation process or a compensatory strategy in the presence of chronic knee pain associated with OA.
منابع مشابه
Patellar kinematics, part I: the influence of vastus muscle activity in subjects with and without patellofemoral pain.
BACKGROUND AND PURPOSE Reduced motor unit activity of the vastus medialis muscle relative to the vastus lateralis muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of vastus muscle motor unit activity on patellar kinematics. SUBJECTS Twenty-three women (mean age=26.8 years, SD=8.5, range=14-46) with a diagnosis of pate...
متن کاملThe effect of whole-body vibration training on the lower extremity muscles\' electromyographic activities in patients with knee osteoarthritis
Background: Whole-Body Vibration Training (WBVT) is a novel neuromuscular training method that has been recently developed as a rehabilitation tool. The purpose of this study was to determine whether WBVT is effective on electromyographic activity of the muscles of the lower limbs in patients with knee osteoarthritis. Methods: The study was designed as a single blinded randomized clinic...
متن کاملRelationship between the EMG ratio of muscle activation and bony structure in osteoarthritic knee patients with and without patellar malalignment.
OBJECTIVE The aim of this study was to compare muscle activation patterns and patellofemoral joint morphologies between patients with knee osteoarthritis with and without patellar malalignment. SUBJECTS The subjects were divided into 3 groups. Group A comprised 11 patients with symptomatic knee osteoarthritis without patellar malalignment. Group B comprised 14 patients with symptomatic knee o...
متن کاملCorrelation between Proprioception Impairment and Onset of Muscle Activities in Knee Osteoarthritis
Background: Muscle strength and proprioception deficits have been recognized in knee OA. Indirect evidence suggests that muscle strength and proprioception deficits may be interrelated. However, these relationships have never been clearly evaluated. Purpose: This study was conducted to investigate relationships between Proprioception deficits and onset of muscle activities during sit to stand i...
متن کامل