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1.
Scand J Med Sci Sports ; 32(10): 1464-1476, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35844051

ABSTRACT

Combined heavy- and light-load ballistic training is often employed in high-performance sport to improve athletic performance and is accompanied by adaptations in muscle architecture. However, little is known about how training affects muscle-tendon unit (MTU) kinematics during the execution of a sport-specific skill (e.g., jumping), which could improve our understanding of how training improves athletic performance. The aim of this study was to investigate vastus lateralis (VL) MTU kinematics during a countermovement jump (CMJ) following combined ballistic training. Eighteen young, healthy males completed a 10-week program consisting of weightlifting derivatives, plyometrics, and ballistic tasks under a range of loads. Ultrasonography of VL and force plate measurements during a CMJ were taken at baseline, mid-test, and post-test. The training program improved CMJ height by 11 ± 13%. During the CMJ, VL's MTU and series elastic element (SEE) length changes and velocities increased from baseline to post-test, but VL's fascicle length change and velocity did not significantly change. It is speculated that altered lower limb coordination and increased force output of the lower limb muscles during the CMJ allowed more energy to be stored within VL's SEE. This may have contributed to enhanced VL MTU work during the propulsion phase and an improved CMJ performance following combined ballistic training.


Subject(s)
Athletic Performance , Muscle Strength , Athletic Performance/physiology , Biomechanical Phenomena , Humans , Male , Muscle Strength/physiology , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/physiology , Quadriceps Muscle , Tendons/diagnostic imaging , Tendons/physiology
2.
Int J Sports Physiol Perform ; 17(5): 733-738, 2022 05 01.
Article in English | MEDLINE | ID: mdl-35203053

ABSTRACT

PURPOSE: Periods away from training and competition are necessary for physical and mental restoration in sport. There is limited research investigating changes to physical qualities in rugby league following prolonged breaks. This study aimed to evaluate the effects of the off-season on muscular power in rugby league. In addition, this study aimed to determine whether the type and volume of training players chose to complete had any relationship to feelings of restoration and/or readiness to return to training. METHODS: Twenty professional rugby league players participated in this study. Lower-body muscular power was evaluated using a countermovement jump prior to the off-season and at the recommencement of training. Players completed a questionnaire to identify training and activities completed during the break and to assess feelings of restoration and readiness to commence training. Linear regression was used to estimate the effects of the number of days off on muscular power. One-way repeated-measures analysis of variance was conducted to examine differences in lower-body power throughout the study. Spearman rank order correlation was calculated to determine the relationship between off-season activities and feelings of restoration and readiness. RESULTS: Peak velocity and peak force significantly increased following the off-season break. There were significant relationships between mental restoration and upper-body resistance training, as well as physical restoration and full-body resistance training. CONCLUSIONS: The off-season has a positive effect on a player's ability to generate muscular power. Coaches may want to encourage players to complete resistance training sessions with the aim simply to maintain training load and potentially help players to feel rested.


Subject(s)
Football , Resistance Training , Humans , Muscle Strength , Rugby , Seasons
3.
Int J Sports Physiol Perform ; 17(2): 278-285, 2022 02 01.
Article in English | MEDLINE | ID: mdl-34853184

ABSTRACT

PURPOSE: Tackling is a fundamental skill in collision sports such as rugby league. Given the complexity of tackling and multitude of strength and power variables available for analysis, this study aimed to predict tackle outcomes in professional rugby league based on strength and power principal components (PCs). METHODS: Twenty-eight rugby league players participated in this study. Maximal strength was assessed via 1 repetition maximum on the back squat, bench press, and bench pull. Lower-body vertical and horizontal power were evaluated using a countermovement jump and standing broad jump. A postmatch analysis of 5 National Rugby League matches was conducted to examine tackling outcomes. PC analysis was performed on the strength and power assessments. The first PCs were retained in each analysis, and a series of Spearman rank-order correlations were conducted between the tackle outcomes and the retained PCs. The PCs significantly related to tackle outcomes were included in the multiple regression analyses to estimate their effect on tackle outcomes. RESULTS: Strength PC was a significant predictor of play-the-ball speed in attack, accounting for 54% of the variance. Countermovement jump PC was a significant predictor of postcontact meters, explaining 19% of the variance. CONCLUSIONS: These findings demonstrate that a range of tackle outcomes may be predicted from strength and power components. The coaching staff may choose to develop programs and testing designed to focus on these components, which may further develop players' tackle outcomes during competition.


Subject(s)
Athletic Performance , Football , Humans , Muscle Strength , Rugby
4.
J Strength Cond Res ; 36(10): 2853-2861, 2022 Oct 01.
Article in English | MEDLINE | ID: mdl-33470597

ABSTRACT

ABSTRACT: Redman, KJ, Wade, L, Whitley, R, Connick, MJ, Kelly, VG, and Beckman, EM. The relationship between match tackle outcomes and muscular strength and power in professional rugby league. J Strength Cond Res 36(10): 2853-2861, 2022-Tackling is a fundamental skill in collision sports, such as rugby league. Match success is largely dependent on a player's ability to complete tackles and tolerate physical collisions. High levels of strength and power are key physical qualities necessary for effective tackling because players are required to generate large forces while pushing and pulling their opponents. The aim of this study was to examine the relationship between tackle outcomes and strength and power qualities in professional rugby league. Fourteen rugby league players participated in this study. Maximal strength was assessed through 1 repetition maximum on the back squat, bench press, and bench pull. Lower-body vertical and horizontal powers were evaluated using a countermovement jump and standing broad jump (SBJ), respectively. Upper-body power was assessed on a plyometric push-up (PPU). Postmatch analysis of 5 National Rugby League matches was conducted to examine tackling outcomes. A series of Spearman's rank-order correlations were used to assess the relationship among match tackle outcomes and strength and power variables. Significant associations were observed between play-the-ball speed and SBJ peak power (rs = -0.74, p = 0.003), postcontact metres and PPU peak power (rs = 0.77, p = 0.002), losing the play-the-ball contest in defence with SBJ distance (rs = 0.70, p = 0.006), and ineffective tackles with PPU concentric impulse (rs = 0.70, p = 0.007). These results suggest the development and maintenance of full-body power to enhance the likelihood of positive tackle outcomes during professional rugby league match-play.


Subject(s)
Athletic Performance , Football , Humans , Muscle Strength , Rugby
5.
J Strength Cond Res ; 35(6): 1604-1610, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34009879

ABSTRACT

ABSTRACT: Redman, KJ, Connick, MJ, Beckman, EM, and Kelly, VG. Monitoring prescribed and actual resistance training loads in professional rugby league. J Strength Cond Res 35(6): 1604-1610, 2021-Coaches devote a considerable amount of time and effort prescribing and selecting exercises to elicit training adaptations. Adherence to the prescribed resistance training load may vary for a number of reasons. The aim of this study was to quantify the difference between prescribed and actual resistance training loads in a team of professional rugby league players. Training loads were quantified using volume load and training intensity throughout a season. The competition was categorized into preseason, early competition, mid-competition, and late competition. Twenty-seven players participated in this study. Four exercises were monitored: back squat, bench press, bench pull, and clean pull. A Friedman's test was used to assess differences between prescribed and actual training loads throughout different phases of the season, for different exercises, and during different weeks in a training block. There were significantly greater differences in prescribed and actual volume loads during the mid-competition in comparison to all other phases of the season (p < 0.01). Although players adherence to prescribed training intensity was significantly greater during the preseason compared with the remainder of the season (p < 0.05), they completed significantly less prescribed training load during week 1 in comparison to week 4 within a training block (p < 0.05). The results of this study demonstrate that regular monitoring of completed resistance training loads may be of greater importance to strength and conditioning coaches to assist in examining potential progress and fatigue or allow for more accurate prescription of load to enhance adaptation throughout a season.


Subject(s)
Football , Resistance Training , Adaptation, Physiological , Exercise , Fatigue , Humans , Muscle Strength
6.
J Sports Sci ; 39(sup1): 81-90, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33704022

ABSTRACT

Conceptually, sports-specific training should not influence measures of impairment used to classify Para athletes. This study evaluated the extent to which measures of strength, range of movement and coordination developed for Para swimming classification changed in response to a performance-focused swimming programme. A five-phase multiple-baseline, single-case experimental research design was utilized. Three participants with cerebral palsy and high support needs completed the 64-week study, which included two 16-week performance-focused swimming training blocks. Swimming speed, isometric shoulder extension strength, shoulder flexion range of movement and upper limb coordination were monitored throughout.Interrupted Time-Series Simulation Method analysis demonstrated large, significant changes in swimming speed (m/s) during the first (d = 2.17; 95% CI 0.45-3.88; p = 0.01) and second (d = 2.59; 95% CI 1.66-3.52; p = 0.00) training blocks. In contrast, changes in strength, range of movement and coordination were predominantly trivial and non-significant. This was the first study to investigate training responsiveness of measures developed for Para sport classification. Results indicate that despite significantly improved swimming performance, impairment measures remained relatively stable, and therefore these measures of impairment may be valid for the purposes of Para swimming classification. Further research is required in elite athletes, different sports and different impairment types.


Subject(s)
Movement/physiology , Muscle Strength/physiology , Physical Conditioning, Human/physiology , Psychomotor Performance/physiology , Sports for Persons with Disabilities/physiology , Swimming/physiology , Adolescent , Athletic Performance/physiology , Cerebral Palsy/physiopathology , Female , Humans , Interrupted Time Series Analysis , Male , Physical Conditioning, Human/methods , Range of Motion, Articular/physiology , Shoulder/physiology , Sports for Persons with Disabilities/classification , Swimming/classification , Time Factors , Upper Extremity/physiology
7.
Int Urogynecol J ; 32(2): 295-302, 2021 02.
Article in English | MEDLINE | ID: mdl-32955598

ABSTRACT

INTRODUCTION AND HYPOTHESIS: Women who perform high-impact activities might be at greater risk of pelvic floor dysfunction (PFD) than those participating in low-impact exercise; however, little is known about whether PFD is more common in one type of high-impact activity than another. The aim of this study was to compare the prevalence of PFD symptoms in women who engage in high-impact activity compared with CrossFit®-brand training (CF). METHODS: An online survey collected data from 1,379 women (521 runners, 858 CF) on exercise participation, parity, and PFD symptoms, via the Pelvic Floor Distress Inventory (PFDI-20). Specific questions from each PFDI-20 subscale further investigated symptoms of pelvic organ prolapse (POP), anal incontinence (AI), as well as stress (SUI) and urgency (UUI) urinary incontinence. RESULTS: Symptoms of POP and AI were significantly higher in runners (POP 12.7%, AI 34.0%) than in CF (POP 7.8%, p = 0.003; AI 27.7%, p = 0.014). There was no significant difference in SUI symptoms between groups (37.0% vs 41.0% respectively, p = 0.141). Vaginally parous runners reported significantly more symptoms of POP (19.0% vs 12.2%, p = 0.023), AI (39.3% vs 27.2%, p = 0.001), and UUI (36.3% vs 29.0%, p = 0.037) than CF. CONCLUSION: Women, particularly parous women, who participate in running, have a higher prevalence of POP and AI symptoms than women who participate in CF. This suggests that CrossFit®-brand training might not be more detrimental to PFD symptoms than other high-impact activity, such as running. This study does not conclude a pelvic floor health benefit of one exercise over another, but highlights that exercise options can be provided to women.


Subject(s)
Fecal Incontinence , Pelvic Floor Disorders , Pelvic Organ Prolapse , Urinary Incontinence , Cross-Sectional Studies , Female , Humans , Pelvic Floor , Pelvic Floor Disorders/epidemiology , Pelvic Floor Disorders/etiology , Pelvic Organ Prolapse/epidemiology , Pregnancy , Surveys and Questionnaires
8.
J Sports Sci ; 39(sup1): 40-61, 2021 Aug.
Article in English | MEDLINE | ID: mdl-32912039

ABSTRACT

A fundamental aspect of classification systems in Paralympic sport is having valid and reliable measures of impairment. However, minimal consensus exists for assessing impaired strength, coordination and range of motion. This review aimed to systematically identify measures of upper body strength, coordination and range of motion impairments that meet the requirements for use in evidence-based classification systems in wheelchair sports. Three electronic databases were searched from 2003 until 31 August 2019 for studies that assessed upper body function of participants and used a measurement tool that assessed strength, coordination or range of motion. The body of evidence for each identified measure was appraised using the Grading of Recommendations Assessment, Development and Evaluation framework. Twenty-three studies were included: ten measured strength and coordination, and six measured range of motion. There was "moderate" confidence in using isometric strength for assessing strength impairment. Tapping tasks for the assessment of coordination impairment received a "low" confidence rating. All other identified measures of coordination and range of motion impairment received a "very low" confidence rating. Several potential measures were identified for assessing upper body strength, coordination and range of motion impairments. Further research is warranted to investigate their use for classification in Paralympic wheelchair sports.


Subject(s)
Athletic Performance/classification , Disability Evaluation , Para-Athletes/classification , Sports for Persons with Disabilities/classification , Ataxia/classification , Ataxia/diagnosis , Bias , Hand Strength , Humans , Isometric Contraction , Muscle Strength , Postural Balance , Psychomotor Performance , Range of Motion, Articular , Reproducibility of Results , Swimming/physiology , Wheelchairs
9.
J Sports Sci Med ; 20(4): 721-731, 2021 12.
Article in English | MEDLINE | ID: mdl-35321143

ABSTRACT

The ability of a rugby league player to express high levels of strength and power is crucial for success in competition. Although researchers have shown relationships between physical attributes and performance, there is a lack of information related to changes in strength and power across various phases of the season. The purpose of this review was to identify the magnitude of change in muscular strength and power during different phases of an elite rugby league season. Percentage change and effect size were calculated to evaluate the magnitude of changes in strength and power. Meta-analyses were conducted to provide pooled estimates and 95% confidence intervals. Twelve studies were included; six reported changes following pre-season training, two during the competition phase and four examined changes over multiple seasons. Pooled estimates indicated large increases in upper and lower body strength 0.81 [0.43-1.19] and 1.35 [0.79-1.91], respectively, following pre-season training. Studies incorporating predominantly heavier loads (p 80% 1 RM) in training reported greater increases in maximal strength than studies completing lighter loads. Four studies used a wave-like programming strategy to obtain large improvements in strength and power 0.91 [0.36-1.45] and 0.90 [0.22-1.57], over multiple seasons. The results of this review highlight the limited current evidence and provides a preliminary reference point for strength and conditioning coaches aiming to develop and maintain strength and power across various stages, and over multiple seasons. Importantly, the results also indicate that higher loads result in greater increases in strength than lower loads.


Subject(s)
Football , Humans , Muscle Strength , Rugby , Seasons
10.
Eur J Sport Sci ; 21(11): 1518-1550, 2021 Nov.
Article in English | MEDLINE | ID: mdl-33028160

ABSTRACT

Measurement of maximum voluntary muscle contractions are effort-dependent - valid measurement requires maximal voluntary effort (MVE) from participants. Submaximal efforts (SMEs) yield invalid and potentially misleading results. This is particularly problematic in medico-legal and Para sport assessments where low strength scores may confer a personal advantage. Therefore, objective methods for accurately differentiating MVE and SME are required. This systematic review aimed to identify, appraise and synthesise evidence from scientific studies evaluating the validity of objective methods for differentiating MVE from SME during maximal voluntary contractions. Four electronic databases were searched for original research articles published in English and secondary references appraised for relevance yielding 25 studies for review. Methods were categorised based on eight distinct underlying theories. For isokinetic strength assessment, methods based on two theories - Strength-measure Ratios and Inter-Trial Strength Consistency - correctly classified 100% MVE and > 92% SME. Consequently, research evaluating the relative suitability of these methods for translation into practice is warranted. During isometric strength assessments, methods based on Deceptive Visual Feedback and Force-length properties warrant further investigation. Both methods yielded statistically significant differences between MVE and SME, with minimal overlap in values, but their sensitivity and specificity have not been evaluated.


Subject(s)
Muscle Strength , Para-Athletes/classification , Physical Examination/standards , Sports for Persons with Disabilities/classification , Humans , Myography/standards , Reproducibility of Results
12.
J Sci Med Sport ; 23(12): 1118-1127, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32507448

ABSTRACT

OBJECTIVES: Para athletes with brain impairment are affected by hypertonia, ataxia and athetosis, which adversely affect starting, sprinting and submaximal running. The aim was to identify and synthesise evidence from studies that have compared the biomechanics of runners with brain impairments (RBI) and non-disabled runners (NDR). DESIGN: Systematic review. METHODS: Five journal databases were systematically searched from inception to March 2020. Included studies compared the biomechanics of RBI (aged>14 years) and NDR performing either block-starts, sprinting, or submaximal running. RESULTS: Eight studies were included, analysing a total of 100 RBI (78M:22F; 18-38 years) diagnosed with either cerebral palsy (n=44) or traumatic brain injury (n=56). Studies analysed block-starts (n=3), overground sprinting (n=3) and submaximal running (n=2), and submaximal treadmill running (n=1). Horizontal velocity during starts, sprinting and self-selected submaximal speeds were lower in RBI. During sprinting and submaximal running, compared with NDR, RBI had shorter stride length, step length, and flight time, increased ground-contact time, increased cadence, and reduced ankle and hip range of motion. In submaximal running, RBI had decreased ankle-power generation at toe-off. CONCLUSIONS: There is limited research and small sample sizes in this area. However, preliminary evidence suggests that RBI had lower sprint speeds and biomechanical characteristics typical of submaximal running speeds in NDR, including increased ground-contact times and reduced stride length, step length, and flight times. Meaningful interpretation of biomechanical findings in RBI is impeded by impairment variability (type, severity and distribution), and methods which permit valid, reliable impairment stratification in larger samples are required.


Subject(s)
Brain Injuries, Traumatic/physiopathology , Cerebral Palsy/physiopathology , Running/physiology , Sports for Persons with Disabilities/physiology , Ankle/physiopathology , Biomechanical Phenomena , Gait/physiology , Hip/physiopathology , Humans , Knee/physiopathology , Range of Motion, Articular
13.
J Strength Cond Res ; 34(4): 982-987, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31972823

ABSTRACT

James, LP, Connick, M, Haff, GG, Kelly, VG, and Beckman, EM. The countermovement jump mechanics of mixed martial arts competitors. J Strength Cond Res 34(4): 982-987, 2020-Gross countermovement jump (CMJ) performance measures are greater in higher-level mixed martial arts (MMA) competitors than lower-level (LL) competitors. Differences in CMJ kinetics and kinematics throughout the action may explain those CMJ performance differences, but this remains to be investigated. After warm-up and familiarization, 27 MMA competitors (divided into 2 groups based on competitive standard; higher level [HL]: n = 14 and LL: n = 13) completed 3 maximal effort CMJs. Power, force, velocity, displacement-time waveforms and eccentric phase displacement, eccentric time, eccentric impulse, and the modified reactive strength index (RSImod) were compared between groups using statistical parametric mapping procedures and independent t-tests. Power (between 65 and 71% of the power-time curve) was greater in the HL than that of the LL group (p = 0.01) despite no differences in eccentric displacement (p = 0.50) or movement time (p = 0.17) between groups. The HL group demonstrated a greater RSImod (p = 0.05) alongside a reduced eccentric time (p = 0.02) and eccentric impulse (p = 0.02). These findings suggest that timing and control of lower-body force production contributed to between-group differences in CMJ performance among MMA competitors.


Subject(s)
Martial Arts/physiology , Muscle Strength/physiology , Muscle, Skeletal/physiology , Adult , Athletic Performance , Biomechanical Phenomena , Humans , Male , Movement , Warm-Up Exercise , Young Adult
14.
Int Urogynecol J ; 31(8): 1551-1558, 2020 08.
Article in English | MEDLINE | ID: mdl-31813038

ABSTRACT

INTRODUCTION AND HYPOTHESIS: The aim of the study was to determine the prevalence of symptoms of pelvic organ prolapse (POP), defined as the sensation of a vaginal bulge, and associated risk factors in women over 18 years of age who lift light (≤15 kg), moderate (16-50 kg), and heavy (>50 kg) weights for exercise, and those who do not lift weights for exercise. METHODS: Women completed an online survey about risk factors for pelvic floor dysfunctions, physical activity history, and pelvic floor symptoms. A question about a vaginal bulge sensation from the validated Pelvic Floor Distress Inventory (PFDI-20) was used to indicate symptoms of POP. Relationships between symptoms of POP and possible risk factors were assessed through logistic regression analysis. RESULTS: Of the 3,934 survey participants, the total prevalence of POP symptoms was 14.4% (n = 566). Category of weight lifted, age, vaginal parity, history of constipation or hemorrhoids, and family history of POP were significantly associated with symptoms. Physically active women lifting weights ≤15 kg were more likely to report symptoms of pelvic organ prolapse than women lifting weights greater than 50 kg (59.7% vs 15.2%; adjusted odds ratio 2.1; 95% confidence interval 1.7-3.4). There was no relationship between POP symptoms and body mass index, forceps delivery, cesarean section, hysterectomy, or menopausal status. CONCLUSION: Physically active women who lift heavy weights for exercise do not have an increased prevalence of POP symptoms. Advice on the contribution of heavy weight lifting as part of a physical activity regime to the pathophysiology of POP requires further investigation.


Subject(s)
Cesarean Section , Pelvic Organ Prolapse , Adolescent , Adult , Cross-Sectional Studies , Exercise , Female , Humans , Pelvic Floor , Pelvic Organ Prolapse/epidemiology , Pelvic Organ Prolapse/etiology , Pregnancy
15.
PM R ; 11(5): 533-547, 2019 05.
Article in English | MEDLINE | ID: mdl-30844129

ABSTRACT

OBJECTIVE: To describe the fitness, function, and exercise training responses of patients following reconstruction of the lower limb with a total femoral (TF), proximal femoral (PF), distal femoral (DF), or proximal tibial (PT) megaprosthesis. TYPE: Systematic review. LITERATURE SURVEY: Five research databases were searched systematically for original studies published in English from 2006 to 2017 that reported fitness, functioning, or exercise training responses for one or more of the four types of lower limb megaprosthesis listed above. METHODOLOGY: Methodologic quality was assessed using a 22-item modified STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist. SYNTHESIS: Of the 5342 articles retrieved, 28 met the inclusion criteria. Thirteen studies reported fitness outcomes, primarily in PT, with none in TF. Impaired knee extensor strength of the affected limb was reported following limb salvage with PF, DF, and PT megaprosthetics. Impaired flexibility was reported following limb salvage with DF and PT megaprosthetics. Functional outcomes were described in all studies and were most commonly reported using the Musculoskeletal Tumor Society (MSTS) system score. Results indicated no clear difference in functional outcomes between megaprosthesis locations. No studies evaluated exercise training responses. CONCLUSIONS: This review identified impairments of lower limb strength and flexibility following limb salvage with a lower limb megaprosthesis. Similarity in functional outcomes for all four reported megaprosthetic locations may indicate a lack of sensitivity in outcome measures, including the absence of items assessing higher-level functioning. Exercise interventions that aim to improve fitness and function in this population have not been evaluated but are required given increasing 5-year survival rates. LEVEL OF EVIDENCE: I.


Subject(s)
Artificial Limbs , Exercise , Limb Salvage , Lower Extremity , Humans
16.
J Strength Cond Res ; 33(11): 2936-2944, 2019 Nov.
Article in English | MEDLINE | ID: mdl-29547489

ABSTRACT

James, LP, Comfort, P, Suchomel, TJ, Kelly, VG, Beckman, EM, and Haff, GG. Influence of power clean ability and training age on adaptations to weightlifting-style training. J Strength Cond Res 33(11): 2936-2944, 2019-The purpose of this investigation was to determine whether weightlifting actions are a viable method for improving athletic performance among weaker, inexperienced lifters when compared with individuals with a greater power clean (PC) result, and hence weightlifting ability and experience. Two groups of males with distinctly different PC performances (higher performance [HP]: N = 8; body mass [BM] = 78.1 ± 4.0 kg; 1 repetition maximum [1RM] PC = 1.08 ± 0.09 kg·BM; lower performance [LP]: N = 8; BM = 82.6 ± 14.0 kg; 1RM PC = 0.78 ± 0.1 kg·BM) and resistance training age (HP: resistance training experience = 3.5 ± 1.2 years; LP: resistance training experience = 1.44 ± 1.50 years) undertook 10 weeks of training involving weightlifting derivatives, in addition to supplemental ballistic and plyometric exercises. Testing of athletic performance (represented by measures derived from the countermovement jump) occurred at baseline, after 5 weeks of training, and after 10 weeks of training. Both groups significantly improved across the majority of outcome variables after training (Hedges' g = 0.98-2.55, p ≤ 0.01-0.05). Only the HP participants experienced significant changes at midtest (g = 0.99-1.27, p ≤ 0.01-0.05), whereas no significant changes were revealed between midtest and posttest in this group. In contrast to this, the LP participants displayed a significant improvement in relative impulse (g = 1.39, p < 0.01) and rate of force development (g = 1.91, p < 0.01) during this final period (p < 0.01). As weaker, inexperienced lifters underwent a significant and meaningful enhancement in maximal neuromuscular measures after weightlifting derivative-focused training, practitioners should consider early implementation of such exercises. However, it is important for coaches to note that a delayed training effect might be present in weaker, less experienced lifters.


Subject(s)
Adaptation, Physiological , Age Factors , Athletic Performance/physiology , Muscle Strength , Weight Lifting/physiology , Adult , Exercise Test , Humans , Male , Plyometric Exercise , Research Design , Resistance Training/methods , Young Adult
17.
Phys Ther Sport ; 32: 34-41, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29730533

ABSTRACT

OBJECTIVES: To evaluate the reliability of swimming-specific range of movement tests developed in order to permit evidenced-based classification in the sport of para swimming. DESIGN: Test-retest intra- and inter-examiner reliability. SETTING: International Swimming training camps and university exercise science departments. PARTICIPANTS: 42 non-disabled participants (mean age 23.2 years) and 24 Para swimmers (mean age 28.5 years). MAIN OUTCOME MEASURES: Intra- and inter-examiner reliability of a battery of novel active range of motion tests. RESULTS: Good to excellent intra-examiner reliability was found for the majority (32/34) of tests in non-disabled participants (ICC = 0.85-0.98). SEM values ranged from 1.18° to 6.11°. Similarly, good to excellent inter-examiner reliability was found for the majority (35/42) of tests in non-disabled participants (ICC = 0.85-0.98). SEM values range from 0.73° to 6.52°. Para swimmers exhibited significantly reduced range of motion compared to non-disabled participants. CONCLUSIONS: The large majority of ROM tests included in this novel battery were reliable both within and between examiners in non-disabled participants. The tests were found to differentiate between non-disabled participants and Para swimmers with hypertonia or impaired muscle power.


Subject(s)
Arthrometry, Articular , Disabled Persons , Range of Motion, Articular , Swimming/physiology , Adult , Female , Humans , Male , Reproducibility of Results , Swimming/classification , Young Adult
18.
Phys Med Rehabil Clin N Am ; 29(2): 313-332, 2018 05.
Article in English | MEDLINE | ID: mdl-29627091

ABSTRACT

Para-sport classification systems define eligibility for Para sport and provide a competition structure that controls for the impact of impairment on the outcome of competition. This article focuses on the classification of para athletes with physical impairments. Development of classification systems based on scientific evidence has only recently been made possible by adoption of a statement of the purpose of classification by the International Paralympic Committee and its member organizations. Rigorous descriptive science can improve extant systems of classification and a recently published study described a data-driven classification structure with validity superior to that of the extant system.


Subject(s)
Athletes/classification , Disabled Persons/classification , Health Personnel , Humans , Rehabilitation , Research Personnel , Specialization
20.
J Strength Cond Res ; 31(5): 1378-1386, 2017 May.
Article in English | MEDLINE | ID: mdl-28415068

ABSTRACT

James, LP, Roberts, LA, Haff, GG, Kelly, VG, and Beckman, EM. Validity and reliability of a portable isometric mid-thigh clean pull. J Strength Cond Res 31(5): 1378-1386, 2017-This study investigated the test-retest reliability and criterion validity of force-time curve variables collected through a portable isometric mid-thigh clean pull (IMTP) device equipped with a single-axial load cell. Fifteen males with ≥6 months of resistance training experience attended two testing sessions. In each session, participants performed an IMTP in 2 separate conditions in a randomized counterbalanced manner. The criterion condition consisted of a closed-chain IMTP configured with a force plate (IMTPf), whereas the experimental test was undertaken using a portable IMTP with data acquired through a single-axial load cell (IMTPl). A very high reliability (coefficient of variation [CV] = 3.10, 90% confidence interval [CI]: 2.4-4.6%; intraclass correlation coefficient [ICC] = 0.96, 90% CI: 0.90-0.98) and acceptable validity (CV = 9.2, 90% CI: 7-14%; ICC = 0.88, 90% CI: 0.71-0.95) were found in the experimental condition for the measure of peak force. However, significant differences were present between the IMTPf and IMTPl (p < 0.0001). Alternate force-time curve variables did not reach acceptable levels of validity or reliability in the experimental condition. The IMTPl is a valid and highly reliable method for assessing peak force. This provides evidence supporting the use of an IMTPl as a cost-effective and portable alternative for those who wish to assess maximal force production in a similar fashion to a traditional IMTP. However, practitioners should be aware that these are slightly different tests.


Subject(s)
Exercise Test/methods , Isometric Contraction/physiology , Muscle Strength/physiology , Resistance Training/methods , Thigh/physiology , Adult , Humans , Male , Reproducibility of Results , Young Adult
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