Activation of Hip Muscles in Runners With Patellofemoral Syndrome

Introduction: Hip motor control deficit and neuromuscular disorders of the gluteus medius influence the mechanics of patellofemoral joints through increased dynamic knee valgus and can lead to Patellofemoral Pain Syndrome (PFPS). Mechanoreceptors can be stimulated by an elastic tape, which sends desired tactile cues via afferent improving the functional support of the musculoskeletal system.

Objective: To analyze the response to hip stabilizer muscle activation in street runners with PFPS through the application of elastic tape therapy.

Methods: The investigators evaluated street runners between the ages of 18 and 45, who run at least 5km/week and had been suffering from pain for at least 3 months. The volunteers had been assessed in relation to their measurements, experience of pain and training routine, their medius muscle (GM) and biceps femoris muscle (BF) had also been tested with surface electromyography through pre-determined performance tests. The participants of both groups wore a bandage for 6 weeks (1 per week). However for the participants of the placebo group the investigators applied a different anatomical path without tension, eliminating all the therapeutic elements. The volunteers were reassessed following the trial.

Hypothesis: Expected to observe that elastic tape therapy do result in any improvement in the activation of hip muscles and improvement of pain in street runners with patellofemoral pain syndrome.

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.

The groups will be followed for six weeks and will be guided them to keep their daily routine. Each week, individuals remain five days with the application of the bandage, and two days without, to avoid possible adverse effects of excessive and constant use of it. After this, a new bandage will be applied by the same trained professional, following the protocols already mentioned. After six weeks, the volunteers return for reevaluation.

Eligibility Criteria:
Inclusion Criteria: Clinical diagnosis of patellofemoral dysfunction issued by a specialist orthopedic knee and provide anterior knee pain of 3 or more on the Visual Analogue Scale (VAS) for a minimum of 8 weeks prior to evaluation;

* Previous retropatellar pain or knee, for at least 3 of the following: up / down stairs, squatting, running, kneeling, sitting for long periods and insidious onset of symptoms unrelated to trauma.

Exclusion Criteria:

* History of severe / traumatic knee injury, surgery history in the locomotor system;
* Patellar luxation history; clinical evidence of meniscus injury; ligamentous instability; patellar tendinitis.
* Presence of neurological, cardiovascular or rheumatologic diseases; pregnancy; diabetes,
* Abnormal sensitivity in the plantar;
* Medication and / or therapy in the last six months and hypersensitivity or allergy to tape.