Activation of Hip Muscles in Runners With Patellofemoral Syndrome: Double-blind Randomized Clinical Trial

Will be recruited individuals 18-45 years of age, of at least running frequency 5 km/week and history of pain in the knee for at least three months in two or more of the following listed activities: up or down stairs, squatting, kneeling , jump, long time sitting or pain on palpation of the lateral side / medial patella.

Will be included individuals without cardiovascular diseases, which have not undergone surgery of the lower limbs in the last two years without back pain and without injury to the hip or knee. They will be excluded from those presenting allergy to the use of elastic bandage or who can not remain with the use of it during the stipulated period. Participants will sign an informed consent and informed, prior to the start of collections.

Data collection was developed with a electromyography (EMG) for muscle data and questionnaire with participants by a blinded examiner initially will be held. The questionnaire consists of the Visual Analogue Scale (VAS). For EMG of the gluteus medius (GM) and biceps femoris (BF), the electrodes are positioned according to the protocols of Surface Electromyography for the Non-Invasive Assessment of Muscles (SENIAM), with the reference electrode located in anterior tibial tuberosity. The application site will be prepared with abrasion and cleansing the skin with 70% alcohol and trichotomy. The maneuver of maximum voluntary isometric contraction (MVIC) will be trained and previously performed the collection, with five seconds support for normalization of data to the gluteus medius and biceps. Among the MVICs every muscle will hold a minute's rest. The muscle activity recorded during the exercises will be expressed in percentage of MVIC. After maneuvers MVIC, individuals will rest for five minutes and then immediately to start the acquisition of electromyographic data during functional tests.

For this, individuals previously will be guided and trained to realize them. During testing, barefoot athletes will be positioned on one foot on the leg with more intense pain complaints, contralateral leg approximately 70 ° of knee flexion, relaxed upper body next to the body, torso upright and keeping focused look a marking affixed to the wall at eye level. In the first test, prompted a squat (AG) of approximately 45 ° of knee flexion, with one foot; in the second test, the same squat will be held, but followed by maximum external rotation (ROT-AG) in the hip support. The cadence of the movement will be standardized and guided by the appraiser to be started and completed in 10 seconds. Functional tests are designed to simulate the action of the hip muscles in the race support phase and motor control of the lower limb.

After electromyographic reviews, be held to randomization to the control group and treatment through and opaque sealed envelopes, by a blinded evaluator. Individuals of both groups will be submitted to the application of the bandage on the leg with pain complaints. For this, a qualified professional trained for the bandage application in relation to anatomical landmarks and elastic tension of the application, without the knowledge, so as to physiology or function thereof. Will be used two techniques in the intervention group. For the placebo group, the application of the bandage will follow a different anatomical path without tension, eliminating all therapeutic process elements.