Objective: To examine the immediate effects of 2 vibration protocols with different vibration frequencies that yielded the same maximum acceleration (106.75ms(-2)) on muscle peak torque and stiffness of knee extensor and flexor.
Design: Randomized crossover study with repeated measures.
Setting: Laboratory setting.
Participants: Recreationally active male adults (N=10).
Intervention: Participants performed 10 bouts of 60-second static half squats intermitted with a 60-second rest period between bouts on a platform with no vibration (control) and a vibration frequency of 26Hz or 40Hz.
Main Outcome Measures: Concentric and eccentric peak torques of knee extensor and flexor were examined within 5 minutes before and after vibration by isokinetic test. Young's modulus as an index of tissue stiffness was determined at quadriceps and hamstring pre- and postvibration by using an ultrasound indentation method.
Results: The 2-way repeated-measures analysis of variance indicated a significant interaction effect between vibration and vibration frequency for knee extensor concentric peak torque (P=.003). The vibration-induced changes of knee extensor concentric peak torque in vibration frequency of 26Hz (14.5Nm) and 40Hz (12.0Nm) were found to be significantly greater than that in controls (-29.4Nm) (P<.05). The change in eccentric peak torque of knee flexor after vibration tended to be greater in 26Hz of vibration frequency when compared with controls (26Hz of vibration frequency vs controls: 13.9±7.1 vs -11.4±5.3Nm, P=.08). No statistically significant differences were obtained in tissue stiffness in the quadriceps and hamstring with any of the conditions.
Conclusions: Our data suggest that whole-body vibration at a frequency of 26Hz and 40Hz preclude the decline in concentric peak torque of knee extensor observed after 10 bouts of 60 seconds of static half squats. A change in muscle mechanical stiffness property as induced by whole-body vibration is not supported by our data.
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http://dx.doi.org/10.1016/j.apmr.2010.07.214 | DOI Listing |
J Funct Morphol Kinesiol
December 2024
Research Unit for Muscle Physiology and Biomechanics (MoB), Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5230 Odense, Denmark.
: Team handball involves a high number of rapid and forceful muscle actions. Progressive heavy-load resistance training is known to enhance mechanical muscle function; however, its transfer into functional performance in team handball athletes remains largely unknown. The current study aimed to analyze the effects of eight weeks undulating heavy-load resistance training on lower limb mechanical muscle function and sports-specific performance in elite female team handball players.
View Article and Find Full Text PDFPLoS One
December 2024
School of Health and Life Sciences, University of Nicosia, Nicosia, Cyprus.
Background: The last phases of a competitive game are when shoulder injuries most commonly happen, and fatigue is thought to be a major contributing factor, perhaps because of reduced proprioception and motor control. The purpose of this study was to investigate the effect of concentric fatigue on proprioception, motor control, and performance of the upper limb in handball players.
Methods: Forty-six right-handed handball players (all males, age 26.
Knee Surg Sports Traumatol Arthrosc
December 2024
Mechanical Engineering Department, Biomechanics Group, Imperial College, London, UK.
Purpose: High-grade femoral trochlear dysplasia is associated with anterior knee pain, patellar maltracking, instability and the development of osteoarthritis. Scientific studies have signified the importance of trochlear resection on the knee extensor mechanism, and dysplasia can be addressed by a groove-deepening trochleoplasty. Alternatively, tibial tubercle anteriorisation has been proposed to reduce patellofemoral joint (PFJ) pressure and alleviate pain from osteoarthritis.
View Article and Find Full Text PDFPhysiother Theory Pract
December 2024
Department of Physiotherapy and Rehabilitation, Atlas University, Istanbul, Turkey.
Background: Dual-task activities, which involve performing two separate tasks simultaneously, often result in reduced motor function and daily activity performance among individuals with knee osteoarthritis (OA).
Objective: This study aimed to investigate the impact of single- and dual-task conditions on muscle strength and performance in individuals with knee OA and examine how cognitive load influences physical task performance in this population.
Methods: Sixty patients with knee OA were included.
iScience
December 2024
Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.
Idiopathic scoliosis is a postural deformity of the spine that not only changes the shape of the spine but may also alter postural control and muscle strength. Although this deformity is more common in some sports, it is not known whether the scoliosis athlete's balance and strength are altered. Balance and strength are essential to perform complex technical movements and prevent injuries.
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