Deficits in neuromuscular control of increasing force in patients with chronic lateral epicondylitis

Objective: This study investigated the neuromuscular control of increasing and releasing force in patients with chronic lateral epicondylitis (CLE). Methods: Fifteen CLE (10 males, 5 females, 46.5 ± 6.3 years) fifteen healthy participants (9 6 45.3 2.5 participated this study. In addition to power grip maximal voluntary contraction (MVC) wrist extension, fluctuation dynamics characteristics inter-spike intervals (ISI) motor units (MUs) various recruitment thresholds extensor carpi radialis brevis (ECRB) longus (ECRL) during a designated force-tracking task trapezoidal target (0%–75%–0% MVC) were assessed. Results: Besides smaller MVC exhibited significantly greater errors ( p = 0.007) fluctuations 0.001) increment than counterparts. Nevertheless, no variables differed between groups release > 0.05). During increment, amplitudes unit action potential ECRB ECRL muscles those heathy counterparts < 0.001). The patient group also higher percentage (MU) lower threshold (<5% ECRL/ECRB MU (>40% muscle, compared group. rate decrease (ISIs) (<10% muscles, 0.005). Conclusion: more pronounced impairment force. is attributed deficits tendon structure degenerative changes larger extensors. To compensate for deficits, progressive increase discharge remaining enhanced generate Significance: observed cannot be fully explained by experimental pain model, which predicts pain-related inhibition on low-threshold units.