Derek N Pamukoff1, Brian Pietrosimone2, Michael D Lewek3, Eric D Ryan2, Paul S Weinhold4, Dustin R Lee5, J Troy Blackburn6. 1. Department of Kinesiology, California State University, Fullerton, Fullerton, CA; Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Curriculum in Human Movement Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC. Electronic address: dpamukoff@fullerton.edu. 2. Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Curriculum in Human Movement Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC. 3. Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Curriculum in Human Movement Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Division of Physical Therapy, The University of North Carolina at Chapel Hill, Chapel Hill, NC. 4. Curriculum in Human Movement Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Department of Orthopedics, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Joint Department of Biomedical Engineering, The University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, NC. 5. Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC. 6. Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Curriculum in Human Movement Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Department of Orthopedics, The University of North Carolina at Chapel Hill, Chapel Hill, NC.
Abstract
OBJECTIVE: To determine the immediate effects of a single session of whole-body vibration (WBV) and local muscle vibration (LMV) on quadriceps function in individuals with anterior cruciate ligament reconstruction (ACLR). DESIGN: Singe-blind, randomized crossover trial. SETTING: Research laboratory. PARTICIPANTS: Population-based sample of individuals with ACLR (N=20; mean age ± SD, 21.1±1.2y; mean mass ± SD, 68.3±14.9kg; mean time ± SD since ACLR, 50.7±21.3mo; 14 women; 16 patellar tendon autografts, 3 hamstring autografts, 1 allograft). INTERVENTIONS: Participants performed isometric squats while being exposed to WBV, LMV, or no vibration (control). Interventions were delivered in a randomized order during separate visits separated by 1 week. MAIN OUTCOME MEASURES: Quadriceps active motor threshold (AMT), motor-evoked potential (MEP) amplitude, Hoffmann reflex (H-reflex) amplitude, peak torque (PT), rate of torque development (RTD), electromyographic amplitude, and central activation ratio (CAR) were assessed before and immediately after a WBV, LMV, or control intervention. RESULTS: There was an increase in CAR (+4.9%, P=.001) and electromyographic amplitude (+16.2%, P=.002), and a reduction in AMT (-3.1%, P<.001) after WBV, and an increase in CAR (+2.7%, P=.001) and a reduction in AMT (-2.9%, P<.001) after LMV. No effect was observed after WBV or LMV in H-reflex, RTD, or MEP amplitude. AMT (-3.7%, P<.001), CAR (+5.7%, P=.005), PT (+.31Nm/kg, P=.004), and electromyographic amplitude (P=.002) in the WBV condition differed from the control condition postapplication. AMT (-3.0% P=.002), CAR (+3.6%, P=.005), and PT (+.30Nm/kg, P=.002) in the LMV condition differed from the control condition postapplication. No differences were observed between WBV and LMV postapplication in any measurement. CONCLUSIONS: WBV and LMV acutely improved quadriceps function and could be useful modalities for restoring quadriceps strength in individuals with knee pathologies.
RCT Entities:
OBJECTIVE: To determine the immediate effects of a single session of whole-body vibration (WBV) and local muscle vibration (LMV) on quadriceps function in individuals with anterior cruciate ligament reconstruction (ACLR). DESIGN: Singe-blind, randomized crossover trial. SETTING: Research laboratory. PARTICIPANTS: Population-based sample of individuals with ACLR (N=20; mean age ± SD, 21.1±1.2y; mean mass ± SD, 68.3±14.9kg; mean time ± SD since ACLR, 50.7±21.3mo; 14 women; 16 patellar tendon autografts, 3 hamstring autografts, 1 allograft). INTERVENTIONS:Participants performed isometric squats while being exposed to WBV, LMV, or no vibration (control). Interventions were delivered in a randomized order during separate visits separated by 1 week. MAIN OUTCOME MEASURES: Quadriceps active motor threshold (AMT), motor-evoked potential (MEP) amplitude, Hoffmann reflex (H-reflex) amplitude, peak torque (PT), rate of torque development (RTD), electromyographic amplitude, and central activation ratio (CAR) were assessed before and immediately after a WBV, LMV, or control intervention. RESULTS: There was an increase in CAR (+4.9%, P=.001) and electromyographic amplitude (+16.2%, P=.002), and a reduction in AMT (-3.1%, P<.001) after WBV, and an increase in CAR (+2.7%, P=.001) and a reduction in AMT (-2.9%, P<.001) after LMV. No effect was observed after WBV or LMV in H-reflex, RTD, or MEP amplitude. AMT (-3.7%, P<.001), CAR (+5.7%, P=.005), PT (+.31Nm/kg, P=.004), and electromyographic amplitude (P=.002) in the WBV condition differed from the control condition postapplication. AMT (-3.0% P=.002), CAR (+3.6%, P=.005), and PT (+.30Nm/kg, P=.002) in the LMV condition differed from the control condition postapplication. No differences were observed between WBV and LMV postapplication in any measurement. CONCLUSIONS: WBV and LMV acutely improved quadriceps function and could be useful modalities for restoring quadriceps strength in individuals with knee pathologies.