Clinical Trial: Effect of Electromyographic Biofeedback on Quadriceps Neuromuscular Function in Patients With Quadriceps Inhibition
Study Status: Terminated
Recruit Status: Terminated
Study Type: Interventional
Official Title: Effect of Electromyographic Biofeedback on Quadriceps Neuromuscular Function
Brief Summary:
Muscle inhibition prevents optimal contraction of the quadriceps muscle due to changes in the nervous system after knee joint injury. Current treatments for muscle inhibition at this time include knee joint cryotherapy and electric stimulation prior to exercise. These treatments, in addition to strengthening exercises, have shown improvements in the quality and strength of muscle contractions however, they have a short window of effectiveness. Electromyographic Biofeedback is proven to be useful in improving quadriceps strength but the mechanism of action remains somewhat unclear. Therefore, the purpose of this investigation is to compare the effectiveness of electromyographic biofeedback supplemented exercise when compared to traditional exercise on quadriceps muscle function in individuals with a history of knee injury and current evidence of quadriceps inhibition. We hypothesize that 14 days of electromyographic biofeedback supplemented exercise will lead to larger gains in quadriceps activation when compared to traditional exercise.
Thirty 18-40 year old participants with a history of knee injury and current evidence of quadriceps muscle inhibition will be enrolled in this single blind randomized controlled trial. Participants will provide written consent prior to all study procedures. Following enrollment, participants will be asked complete questionnaires related to knee related function, current levels of pain, and current activity level followed by completion of baseline measurements.
- We will use the superimposed burst technique to quadriceps muscle activation.
- We will measure the Hoffmann reflex response of the quadriceps with surface electromyography. We will measure this signal with surface electromyography electrodes that record the activity of
Detailed Summary:
Screening Subjects will be asked to complete a brief questionnaire about their lower extremity, which will be used to determine if they exhibit any of the exclusionary criteria (administered by the Study Coordinator). This will include past medical history, headache/ migraine history, and any drugs/medications they are currently taking (which might influence the excitability threshold Hoffman reflex (H-reflex) measurement or central activation ratio). Subjects will also undergo quadriceps central activation ratio testing to determine the level of quadriceps inhibition. Upon review of the questionnaire and quadriceps central activation ratio, the study coordinator will determine a subject's eligibility (based on the inclusion and exclusion criteria). We will also collect age, height and weight for all subjects. Participants that qualify will provide written at this time which will be documented by the investigator.
Quadriceps Central Activation Ratio We will use the superimposed burst technique to measure quadriceps muscle strength and to estimate quadriceps activation by calculating the central activation ratio. Subjects will be secured to a chair (Biodex multi-mode dynamometer) with their knees and hips bent to approximately 90 degrees. Subjects will perform a maximal, voluntary isometric knee extension contraction (MVIC) with continuous verbal encouragement from the tester. Once the MVIC reaches a plateau (representing subjects' maximal effort) an electrical stimulus will be manually triggered and delivered directly to the quadriceps through 2 stimulating electrodes which will be secured to the subjects' anterior thigh. The stimulus will cause the quadriceps to twitch resulting in a temporary increase in force production which we will measure. A ratio between the MVIC force and the highest force achieved due to the electrical stimulation will be calculated - this is cal
Sponsor: University of Miami
Current Primary Outcome: Change From Baseline in Quadriceps Central Activation Ratio [ Time Frame: Baseline and 14 days ]
Subjects will be secured to a chair (Biodex multi-mode dynamometer) with their knees and hips bent to approximately 90-degrees. Subjects will perform a maximal, voluntary isometric knee extension contraction (MVIC) with continuous verbal encouragement from the tester. Once the MVIC reaches a plateau (representing subjects' maximal effort) an electrical stimulus will be manually triggered and delivered directly to the quadriceps through 2 stimulating electrodes which will be secured to the subjects' anterior thigh. The stimulus will cause the quadriceps to twitch resulting in a temporary increase in force production which we will measure. A ratio between the MVIC force and the highest force achieved due to the electrical stimulation will be calculated - this is called the central activation ratio.
Original Primary Outcome: Same as current
Current Secondary Outcome: Change From Baseline in Quadriceps Hoffmann Reflex [ Time Frame: Baseline and 14 days ]
We will record muscle reflex activity by delivering a short percutaneous (through the skin) electrical stimulation to femoral nerve located in the inguinal fold. We will measure the reflex response of the quadriceps with surface electromyography. Subjects will be positioned comfortably in a lying-down position on a treatment table. Stimuli will be delivered to the femoral nerve by increasing the intensity in small increments with a 10-sec rest interval after each stimulus, until the maximum H-reflex amplitude is recorded (Hmax). The H-reflex represents the proportion of the quadriceps motor neuron pool that is available for voluntary contraction and the M-wave represents the total volume of the quadriceps motor neuron pool and will be used to normalize the H-reflex recordings as H:M ratio. This measurement will be performed bilaterally.
Original Secondary Outcome: Same as current
Information By: University of Miami
Dates:
Date Received: March 20, 2014
Date Started: December 2013
Date Completion:
Last Updated: December 3, 2016
Last Verified: December 2016
