3 Clinical Trials for Various Conditions
The primary purposes of the proposed study is 1) To examine the changes of muscle fiber cross-sectional areas in the leg extensor muscles (vastus lateralis) pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction and 2) To examine changes in motor unit size (a non-invasive measure of muscle fiber size) in the leg extensor muscles (vastus lateralis) pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction.
The purpose of this research study is to determine whether low intensity resistance training with concurrent application of a peripheral blood flow restriction device to the exercising limb will elicit increased quadriceps strength, functional gains, ability to complete knee-related activities of daily living, mobility, and quality of life in individuals at risk for developing symptomatic knee osteoarthritis (OA). It is known that higher quadriceps strength is protective against developing symptomatic knee OA.1 However, people at risk for knee OA frequently do not tolerate the high intensity resistance training that is generally believed necessary to increase muscle strength. Partial blood flow restriction (PBFR) to the exercising muscle has been reported to result in strength gains, while requiring lower levels of joint loading.2 This method may be better tolerated, enabling efficacious exercise in older adults who may not tolerate high knee joint loads. To asses the efficacy of a 4 week low-intensity resistance training program with concurrent application of PBFR to the exercising limbs to improve quadriceps strength and size, leg muscle power, and mobility in individuals at risk for developing symptomatic knee osteoarthritis,we will test the following hypotheses. In comparison with low-intensity resistance training without use of PBFR, a four-week low-intensity resistance-training program with PBFR will: Primary Hypothesis: Increase (a) double leg-press 1RM strength and (b) isokinetic knee extensor strength Secondary Hypotheses: 1. Increase quadriceps muscle volume assessed by MRI 2. Increase lower limb muscle power on (a) double leg-press at 40% 1RM and (b) a timed stair climb 3. Not adversely effect knee pain or quality of life assessed by the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire
The objective of the proposed research is to assess the efficacy of an eight-week, efficient and tolerable, low-intensity resistance-training program with concurrent application of partial blood flow restriction (PBFR) for improving quadriceps strength and volume in women with risk factors for incident symptomatic or progressive knee OA. This specific aim will be achieved through a randomized, controlled trial, comparing low intensity training with and without PBFR. There have been numerous reports of exercise interventions in people with knee osteoarthritis. However, this research is novel in that it will be the first to use a low intensity regimen that will minimize forces on the knee while still having the potential to lead to clinically meaningful strength gains in older adults with risk factors for incident symptomatic or progressive knee OA.