Neuromuscular Electrical Stimulation on Patellofemoral Pain

Objective this study is to analyze the effects of an intervention protocol with neuromuscular electrical stimulation in the vastus medialis obliquus and gluteus medius (GM) associated with exercises on electromyographic activity, muscle performance, self-reported functionality and pain of women with patellofemoral pain.

This is a randomized, blinded trial in which 40 women, aged 18-30 years, will be randomized into 2 groups: Stimulation and Exercise Group (SEG) - will perform an exercise protocol associated with stimulation in the vastus medialis (VM) and gluteus medius (GM) muscles. Exercises Group (ExG) - will perform the same protocol of exercises of the previous group, however, without association with neuromuscular electrical stimulation. The intervention will occur twice a week for eight weeks. All volunteers will be submitted to the evaluation of the electromyographic activity of the VM, the GM and the vastus lateralis, the dynamometric parameters, the intensity of the pain and the functionality, in four moments: 72h hours before the beginning of the intervention; after 4 weeks of intervention; after 8 weeks of intervention; after 16 weeks from the start of the intervention (eight weeks after the end of the protocol). In this way, the investigators will investigate the applicability of the proposed trial with the use of neuromuscular electrical stimulation and identify the effects of this resource in the treatment of PFP.

8-week exercise program, twice a week, with neuromuscular eletrical stimulation on vastus medialis and gluteus medius.

Exercise protocol associated with neuromuscular electrical stimulation on vastus medialis and gluteus medius. Parameters: rectangular pulse shape, biphasic, symmetrical, pulse duration of 200μs, interbust interval of 10ms and frequency of 2.500Hz modulated in 50 bursts.

Evaluation of pain level in the knee using the Numerical Pain Scale, graded from 0 to 10, where 0 indicates absence of pain and 10 indicates the worst pain imaginable.

Evaluation of knee function using the Anterior Knee Pain Scale, that is a questionnaire encompassing 13 items related to different levels of knee function, with scores ranging from zero (representing the highest possible deficit) to 100 (meaning that the subject does not present any deficit).

Evaluation of the amplitude oh the electromyographic sinal (RMS) of vastus medialis, vastus lateralis and gluteus medius.

Evaluation of time of muscle activation electromyographic (onset) of vastus medialis, vastus lateralis and gluteus medius.

Evaluation of isokinetic variable peak torque normalized for body weight (%) of knee extensors and hip abductors.

Inclusion Criteria: Present anterior or retropatellar pain during at least two of the following functional activities: sitting for long periods, going up or down stairs, running, kneeling down, crouching or jumping; A minimum pain score of three on the numerical pain scale, at the last 24 hours, with insidious and non-traumatic onset of symptoms for at least one month. Exclusion Criteria: History of surgery, trauma or an osteomioarticular system injury in the lower limbs in the last six months; Other pathology associated with the knee joint and could not have performed physical therapy treatment in the last twelve weeks; Body mass index greater than 30; Pregnancy or breastfeeding; Contraindications for the application of neuromuscular electrical stimulation; Intolerance or non-acceptance of electric current; Missing more than two intervention sessions.