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Which Jump Variables Should Be Used to Assess Explosive Leg Muscle Function?

Warren Young, Stuart Cormack, and Michael Crichton

Purpose:

The main purpose of this study was to determine the relationships between countermovement jump (CMJ) variables and acceleration and maximum speed performance.

Methods:

Twenty-three elite Australian football players were tested on a CMJ, which yielded several kinematic and kinetic variables describing leg muscle function. A 40 m sprint was also conducted to assess acceleration (10 m time) and an estimate of maximum speed (fying 20 m time). Players from one Australian Football League (AFL) club were tested and Pearson correlations for CMJ variables and sprint performance were calculated.

Results:

Jump height, peak velocity, peak force, and peak power had less than 50% common variance, and therefore represented independent expressions of CMJ performance. Generally, the correlations between CMJ variables and sprinting performance were stronger for maximum speed (small to large effect sizes) than for acceleration (trivial to moderate sizes). The variable that produced the strongest correlation with acceleration was jump height (r = -0.430, P = .041) and with maximum speed was peak power/weight (r = -0.649, P = .001).

Conclusions:

The results indicate that if an integrated system comprising a position transducer and a force platform is available for CMJ assessment, jump height and peak power/weight are useful variables to describe leg muscle explosive function for athletes who perform sprints.

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Peripheral Muscle Function During Repeated Changes of Direction in Basketball

Davide Ferioli, Ermanno Rampinini, Andrea Bosio, Antonio La Torre, and Nicola A. Maffiuletti

Peripheral Muscle Function of Knee Extensors Measured During the Multistage Change-of-Direction Exercise Division I, n = 27 Division II, n = 25 Division III, n = 32 Division VI, n = 27 PT max , N·m 73.1 (17.4) 71.5 (12.7) 65.0 (12.2) 61.1 (8.3) Fatigue, % 10.5 (8.3) 13.5 (12.2) 15.7 (16.8) 28.7 (23.9) MP max

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Effect of Aging on Trunk Muscle Function and Its Influence on Falls Among Older Adults

Jaqueline M. Porto, Sállua B. Spilla, Luciana M. Cangussu-Oliveira, Renato C. Freire Júnior, Ana Paula M. Nakaishi, and Daniela C.C. de Abreu

the association of trunk muscle strength with falls ( Granacher et al., 2013 ; Kasukawa et al., 2010 ; Pfeifer et al., 2001 ). In addition, we detected no studies investigating the influence of other trunk muscle function parameters, such as the rate of torque development (RTD) and torque steadiness

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Effect of Yoga or Physical Exercise on Muscle Function in Rural Indian Children: A Randomized Controlled Trial

Sonal Kasture, Anuradha Khadilkar, Raja Padidela, Ketan Gondhalekar, Radhika Patil, and Vaman Khadilkar

Muscle function (MF) is a crucial fitness component throughout the life span, and measures to improve it need to be taken beginning in childhood. Previous studies in children have shown strong association between poor MF and adverse health outcomes such as metabolic syndrome, higher cardiometabolic

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Association Between Inspiratory Muscle Function and Balance Ability in Older People: A Pooled Data Analysis Before and After Inspiratory Muscle Training

Francesco V. Ferraro, James P. Gavin, Thomas W. Wainwright, and Alison K. McConnell

significant decline in inspiratory muscle function ( Britto et al., 2009 ) and an increase in pulmonary inflammation, known as senile emphysema ( Janssens et al., 1999 ). These progressive declines may impair the inspiratory muscles’ contribution to their secondary role in balance stabilization, as evident in

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Lower Extremity Muscle Functions during Full Squats

D.G.E. Robertson, Jean-Marie J. Wilson, and Taunya A. St. Pierre

The purpose of this research was to determine the functions of the gluteus maximus, biceps femoris, semitendinosus, rectus femoris, vastus lateralis, soleus, gastrocnemius, and tibialis anterior muscles about their associated joints during full (deep-knee) squats. Muscle function was determined from joint kinematics, inverse dynamics, electromyography, and muscle length changes. The subjects were six experienced, male weight lifters. Analyses revealed that the prime movers during ascent were the monoarticular gluteus maximus and vasti muscles (as exemplified by vastus lateralis) and to a lesser extent the soleus muscles. The biarticular muscles functioned mainly as stabilizers of the ankle, knee, and hip joints by working eccentrically to control descent or transferring energy among the segments during ascent. During the ascent phase, the hip extensor moments of force produced the largest powers followed by the ankle plantar flexors and then the knee extensors. The hip and knee extensors provided the initial bursts of power during ascent with the ankle extensors and especially a second burst from the hip extensors adding power during the latter half of the ascent.

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Effect of Vitamin D on Muscle Function and Injury in Elite Adolescent Dancers: A Randomized Double-Blind Study

Matthew A. Wyon, Roger Wolman, Nicolas Kolokythas, Karen Sheriff, Shaun Galloway, and Adam Mattiussi

to examine whether vitamin D supplementation can improve muscle function and injury incidence in adolescent elite dancers. Materials and Methods Experimental Design The study implemented a randomized double-blind methodology. Supplementation was organized by an independent researcher who prepared the

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Changes in Mobility and Muscle Function of Children with Cerebral Palsy after Gait Training: A Pilot Study

Amy K. Hegarty, Max J. Kurz, Wayne Stuberg, and Anne K. Silverman

The goal of this pilot study was to characterize the effects of gait training on the capacity of muscles to produce body accelerations and relate these changes to mobility improvements seen in children with cerebral palsy (CP). Five children (14 years ± 3 y; GMFCS I-II) with spastic diplegic CP participated in a 6-week gait training program. Changes in 10-m fast-as-possible walking speed and 6-minute walking endurance were used to assess changes in mobility. In addition, musculoskeletal modeling was used to determine the potential of lower-limb muscles to accelerate the body’s center of mass vertically and forward during stance. The mobility changes after the training were mixed, with some children demonstrating vast improvements, while others appeared to be minimal. However, the musculoskeletal results revealed unique responses for each child. The most common changes occurred in the capacity for the hip and knee extensors to produce body support and the hip flexors to produce body propulsion. These results cannot yet be generalized to the broad population of children with CP, but demonstrate that therapy protocols may be enhanced by modeling analyses. The pilot study results provide motivation for gait training emphasizing upright leg posture, mediolateral balance, and ankle push-off.

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Tart Cherry Juice: No Effect on Muscle Function Loss or Muscle Soreness in Professional Soccer Players After a Match

Will Abbott, Callum Brashill, Adam Brett, and Tom Clifford

of the subsequent inflammatory response remains debated, 3 , 4 there is evidence to suggest that it might contribute to the delayed recovery of muscle function typically observed in the days following strenuous exercise. 5 – 7 This has led to growing interest in the use and efficacy of anti

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Curcumin Attenuates Delayed-Onset Muscle Soreness and Muscle Function Deficits Following a Soccer Match in Male Professional Soccer Players

William Abbott, Emily J. Hansell, Adam Brett, Jakob Škarabot, Lewis J. James, and Tom Clifford

exercise, 1 impacting exercise performance in the subsequent days. Several studies have shown that soccer, an intense intermittent sport, evokes deficits in muscle function and DOMS that can last for 72 hours following matches. 4 As soccer players often have limited recovery time between matches (48