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PubMed | University of Ljubljana and Strength and Conditioning Research Ltd
Type: Journal Article | Journal: International journal of sports physical therapy | Year: 2015

Increased flexibility is often desirable immediately prior to sports performance. Static stretching (SS) has historically been the main method for increasing joint range-of-motion (ROM) acutely. However, SS is associated with acute reductions in performance. Foam rolling (FR) is a form of self-myofascial release (SMR) that also increases joint ROM acutely but does not seem to reduce force production. However, FR has never previously been studied in resistance-trained athletes, in adolescents, or in individuals accustomed to SMR.To compare the effects of SS and FR and a combination of both (FR+SS) of the plantarflexors on passive ankle dorsiflexion ROM in resistance-trained, adolescent athletes with at least six months of FR experience.Eleven resistance-trained, adolescent athletes with at least six months of both resistance-training and FR experience were tested on three separate occasions in a randomized cross-over design. The subjects were assessed for passive ankle dorsiflexion ROM after a period of passive rest pre-intervention, immediately post-intervention and after 10, 15, and 20 minutes of passive rest. Following the pre-intervention test, the subjects randomly performed either SS, FR or FR+SS. SS and FR each comprised 3 sets of 30 seconds of the intervention with 10 seconds of inter-set rest. FR+SS comprised the protocol from the FR condition followed by the protocol from the SS condition in sequence.A significant effect of time was found for SS, FR and FR+SS. Post hoc testing revealed increases in ROM between baseline and post-intervention by 6.2% for SS (p < 0.05) and 9.1% for FR+SS (p < 0.05) but not for FR alone. Post hoc testing did not reveal any other significant differences between baseline and any other time point for any condition. A significant effect of condition was observed immediately post-intervention. Post hoc testing revealed that FR+SS was superior to FR (p < 0.05) for increasing ROM.FR, SS and FR+SS all lead to acute increases in flexibility and FR+SS appears to have an additive effect in comparison with FR alone. All three interventions (FR, SS and FR+SS) have time courses that lasted less than 10 minutes.2c.


Beardsley C.,Strength and Conditioning Research Ltd | Contreras B.,Auckland University of Technology
Strength and Conditioning Journal | Year: 2014

Studies support the use of kettlebells for improving power, although evidence for using them to improve strength and aerobic fitness is still equivocal. Studies investigating the biomechanical properties of kettlebell training have been fruitful, and it may be useful for developing sprint running performance and for injury prevention. However, we still do not know the optimal loads for maximizing system and joint power production, how the mechanics, joint moments, and electromyographic activity changes as loads increase during kettlebell swings, nor whether kettlebell training transfers to sports performance. Copyright © 2014 National Strength and Conditioning Association.


Beardsley C.,Strength and Conditioning Research Ltd | Contreras B.,Auckland University of Technology
Strength and Conditioning Journal | Year: 2014

HIP EXTENSION MOMENTS INCREASE TO A MUCH GREATER DEGREE THAN KNEE EXTENSION MOMENTS WITH INCREASING LOADS DURING THE SQUAT, LUNGE, AND DEADLIFT EXERCISES AND WITH INCREASING RUNNING SPEEDS, JUMP HEIGHTS, AND LATERAL AGILITY MANEUVERS. THEREFORE, HIP EXTENSION TRAINING SHOULD BE PRIORITIZED IN ATHLETIC CONDITIONING BY (A) USING HIP-DOMINANT EXERCISES IN THE ATHLETE'S PROGRAM, (B) EMPHASIZING HEAVIER LOADS DURING COMPOUND LOWER-BODY RESISTANCE EXERCISES AS THE ATHLETE MATURES, AND (C) INCORPORATING LOADS THAT MAXIMIZE THE HIP EXTENSION MOMENT DURING EXPLOSIVE LOWER-BODY TRAINING. Copyright © National Strength and Conditioning Association. © Lippincott Williams & Wilkins.


Beardsley C.,Strength and Conditioning Research Ltd | Contreras B.,Auckland University of Technology
Strength and Conditioning Journal | Year: 2014

The functional movement screen (FMS) is a pre-participation screening tool comprising 7 individual tests for which both individual scores and an overall score are given. The FMS displays both interrater and intrarater reliability but has been challenged on the basis of a lack of validity in several respects. The FMS seems to have some degree of predictive ability for identifying athletes who are at an increased risk of injury. However, a poor score on the FMS does not preclude athletes from competing at the highest level nor does it differentiate between athletes of differing abilities. Copyright © National Strength and Conditioning Association. Copyright © Lippincott Williams & Wilkins.


PubMed | Auckland University of Technology, Arizona State University and Strength and Conditioning Research Ltd
Type: | Journal: PeerJ | Year: 2015

Muscle hypertrophy and atrophy occur frequently as a result of mechanical loading or unloading, with implications for clinical, general, and athletic populations. The effects of muscle hypertrophy and atrophy on force production and joint moments have been previously described. However, there is a paucity of research showing how hypertrophy and atrophy may affect moment arm (MA) lengths. The purpose of this model was to describe the mathematical relationship between the anatomical cross-sectional area (ACSA) of a muscle and its MA length. In the model, the ACSAs of the biceps brachii and brachialis were altered to hypertrophy up to twice their original size and to atrophy to one-half of their original size. The change in MA length was found to be proportional to the arcsine of the square root of the change in ACSA. This change in MA length may be a small but important contributor to strength, especially in sports that require large joint moments at slow joint angular velocities, such as powerlifting. The paradoxical implications of the increase in MA are discussed, as physiological factors influencing muscle contraction velocity appear to favor a smaller MA length for high velocity movements but a larger muscle MA length for low velocity, high force movements.


PubMed | Lehman College, CUNY, Auckland University of Technology, Arizona State University, Strength and Conditioning Research Ltd and Edith Cowan University
Type: | Journal: PeerJ | Year: 2015

Background. The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90) hip extension against manual resistance applied to the distal thigh (PRONE), to a novel position, the standing glute squeeze (SQUEEZE). Methods. Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg), before three maximum voluntary isometric contraction (MVIC) trials for each position were obtained in a randomized, counterbalanced fashion. Results. No statistically significant (p < 0.05) differences were observed between PRONE (upper: 91.94%; lower: 94.52%) and SQUEEZE (upper: 92.04%; lower: 85.12%) for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects. Conclusions. In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.


PubMed | Auckland University of Technology, Arizona State University and Strength and Conditioning Research Ltd
Type: | Journal: PeerJ | Year: 2015

Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 3.3 years; height = 170 9.18 cm; mass = 67.7 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86 (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearsons r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = -1.39 (-5.53, +2.75); t(22) = -0.70; p = 0.4933; Cohens d = - 0.15 (-0.58, 0.29)) or rectus femoris length (change = -0.005 (-0.013, +0.003); t(22) = -1.30; p = 0.2070; Cohens d = - 0.27 (-0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol.


Beardsley C.,Strength and Conditioning Research Ltd | Skarabot J.,University of Jyväskylä
Journal of Bodywork and Movement Therapies | Year: 2015

Background: Self-myofascial release (SMFR) is a type of myofascial release performed by the individual themselves rather than by a clinician, typically using a tool. Objectives: To review the literature regarding studies exploring acute and chronic clinical effects of SMFR. Methods: PubMed and Google Scholar databases were searched during February 2015 for studies containing words related to the topic of SMFR. Results: Acutely, SMFR seems to increase flexibility and reduce muscle soreness but does not impede athletic performance. It may lead to improved arterial function, improved vascular endothelial function, and increased parasympathetic nervous system activity acutely, which could be useful in recovery. There is conflicting evidence whether SMFR can improve flexibility long-term. Conclusion: SMFR appears to have a range of potentially valuable effects for both athletes and the general population, including increasing flexibility and enhancing recovery. © 2015 Elsevier Ltd.


PubMed | University of Jyväskylä and Strength and Conditioning Research Ltd
Type: Journal Article | Journal: Journal of bodywork and movement therapies | Year: 2015

Self-myofascial release (SMFR) is a type of myofascial release performed by the individual themselves rather than by a clinician, typically using a tool.To review the literature regarding studies exploring acute and chronic clinical effects of SMFR.PubMed and Google Scholar databases were searched during February 2015 for studies containing words related to the topic of SMFR.Acutely, SMFR seems to increase flexibility and reduce muscle soreness but does not impede athletic performance. It may lead to improved arterial function, improved vascular endothelial function, and increased parasympathetic nervous system activity acutely, which could be useful in recovery. There is conflicting evidence whether SMFR can improve flexibility long-term.SMFR appears to have a range of potentially valuable effects for both athletes and the general population, including increasing flexibility and enhancing recovery.


PubMed | Staffordshire University, Sport Science Tutor and Strength and Conditioning Research Ltd
Type: | Journal: PeerJ | Year: 2016

Objective. The purpose of this study was to investigate the reliability of a digital pelvic inclinometer (DPI) for measuring sagittal plane pelvic tilt in 18 young, healthy males and females. Method. The inter-rater reliability and test-re-test reliabilities of the DPI for measuring pelvic tilt in standing on both the right and left sides of the pelvis were measured by two raters carrying out two rating sessions of the same subjects, three weeks apart. Results. For measuring pelvic tilt, inter-rater reliability was designated as good on both sides (ICC = 0.81-0.88), test-re-test reliability within a single rating session was designated as good on both sides (ICC = 0.88-0.95), and test-re-test reliability between two rating sessions was designated as moderate on the left side (ICC = 0.65) and good on the right side (ICC = 0.85). Conclusion. Inter-rater reliability and test-re-test reliability within a single rating session of the DPI in measuring pelvic tilt were both good, while test-re-test reliability between rating sessions was moderate-to-good. Caution is required regarding the interpretation of the test-re-test reliability within a single rating session, as the raters were not blinded. Further research is required to establish validity.

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