Entrainment of vastus medialis complex activity differs between genders. Issue 4 (29th December 2015) - Tenan, Matthew S.
ABSTRACT: Introduction : That the vastus medialis oblique (VMO) is a functional unit of the vastus medialis (VM) is disputed. Delayed VMO activation predicts patellofemoral pain, which has higher rates in women. Methods : Single MUs and surface electromyogram (EMG) were collected from the VMO and VM of 9 men and 9 women. Men were tested once; women were tested during 5 menstrual phases. Coherence was assessed for motor unit (MU) firings within and between the VM and VMO using multilevel logistic models to determine statistical significance. Results : Compared with women, men have 741% (MU pairs) and 256% (MU‐EMG pairs) greater odds of common drive (0–5 Hz ) coherent oscillations. MU pairs from the VMO and the dual VM/VMO complex have 228% and 212% greater odds of coherent oscillations in the beta band (15–35 Hz ) compared with VM pairs. Conclusions : The VM and VMO are neurologically different muscles; control of the VM complex is sexually dimorphic. Muscle Nerve 53 : 633–640, 2016