The severity of experimentally induced pain influences muscular performance during maximal voluntary isometric knee extensor contractions

Experimental pain has been shown to decrease maximal muscular performance (Ervilha et al., 2004) with evidence to suggest that motor unit firing rate is inversely correlated to perceived pain intensity when pain is induced via invasive hypertonic saline injections (Farina et al., 2004). The aims of the present study were to examine the influence of the severity of pain induced by a non-invasive gross pressure device (GPD) on muscular performance in the lower limb. Thirty-one healthy male participants (mean ± SD; age = 32.7 ± 12.3yr, height = 1.8 ± 0.1m, mass = 85.3 ±12.1kg) volunteered for the study after giving written, informed consent, with ethical approval granted by the University of Northampton’s ethics committee. Isometric knee extensor joint moment and electromyographic (EMG) activity of the vastus lateralis (VL) and semitendinosus (ST) muscles were measured during maximum voluntary isometric contractions (MVC) within control and three experimental conditions (100%, 200% and 300% of pain perception threshold). A repeated measures ANOVA determined significance between conditions; post-hoc analysis with Bonferroni correction determined the location of any significant differences. Statistical significance was accepted at p0.05). Similar significant reductions (p