Epidemiology of Common Injuries in the Volleyball Athlete.

PURPOSE OF REVIEW: To review the recent literature regarding the epidemiology of injuries in the volleyball athlete across all levels of play and to discuss areas where further studies are needed. RECENT FINDINGS: Injury epidemiology for volleyball at the collegiate and high school level has been supported by a longitudinal injury surveillance program through the NCAA Injury Surveillance System (NCAA ISS) and High School Reporting Information Online (HS RIO) for the past 30 years. The creation of the FIVB Injury Surveillance System (FIVB ISS) in 2010 shows promise in advancing the literature on the injury at the professional level, and further studies on beach volleyball injuries are needed. Overall, injury patterns in volleyball in the past decade showed similar distribution to prior studies, but the rate of injury may be decreasing. Common injuries in volleyball include ankle sprains, patellar tendinopathy, finger and thumb sprains, overuse injuries of the shoulder, and concussions. Injury surveillance from the NCAA has demonstrated injury trends at the collegiate level, but further longitudinal studies are needed to evaluate injury at the professional level and for beach volleyball to help develop injury prevention strategy.

Common High-Speed Running Thresholds Likely Do Not Correspond to High-Speed Running in Field Sports.

ABSTRACT: Freeman, BW, Talpey, SW, James, LP, Opar, DA, and Young, WB. Common high-speed running thresholds likely do not correspond to high-speed running in field sports. J Strength Cond Res 37(7): 1411-1418, 2023-The purpose of this study was to clarify what percentage of maximum speed is associated with various running gaits. Fifteen amateur field sport athletes (age = 23 ± 3.6 years) participated in a series of 55-meter running trials. The speed of each trial was determined by instructions relating to 5 previously identified gait patterns (jog, run, stride, near maximum sprint, and sprint). Each trial was filmed in slow motion (240 fps), whereas running speed was obtained using Global Positioning Systems. Contact time, stride angle, and midstance free-leg knee angle were determined from video footage. Running gaits corresponded with the following running speeds, jogging = 4.51 m·s -1 , 56%Vmax, running = 5.41 m·s -1 , 66%Vmax , striding = 6.37 m·s -1 , 78%Vmax, near maximum sprinting = 7.08 m·s -1 , 87%Vmax, and sprinting = 8.15 m·s -1 , 100%Vmax. Significant ( p < 0.05) increases in stride angle were observed as running speed increased. Significant ( p < 0.05) decreases were observed in contact time and midstance free-leg knee angle as running speed increased. These findings suggest currently used thresholds for high-speed running (HSR) and sprinting most likely correspond with jogging and striding, which likely underestimates the true HSR demands. Therefore, a higher relative speed could be used to describe HSR and sprinting more accurately in field sports.

A Systematic Review of Telehealth and Sport-Related Concussion: Baseline Testing, Diagnosis, and Management.

Background: The use of telehealth has increased as a result of the COVID-19 pandemic. As sports at all levels resume, sports medicine physicians may be interested in how telehealth can be used for concussion care. Questions/Purpose: We sought to assess how telehealth has been used in the baseline testing, diagnosis, and/or management of concussion. Secondarily, we sought to assess the strengths and weaknesses of telehealth for concussion care and identify aspects of concussion care for which telehealth has not yet been studied. Methods: A systematic review was performed in September 2020 of PubMed and Embase using the following terms: concuss*, "mild traumatic brain," "head injur*," telehealth, telemedicine, telecare, "mobile health," m-health, virtual. Studies included were original research articles investigating the use of telehealth in the care of concussion (including baseline testing, diagnosis, and management), published in English, and had full text available. Results: A total of 356 articles were screened, of which 5 were determined to meet inclusion criteria. These articles described the use of telehealth for managing concussion in military and rural settings. No articles involved the use of telehealth for baseline concussion testing of athletes or for sideline evaluation. Conclusion: Despite the limited original research on the use of telehealth for concussion care, the articles identified provide a foundation for exploring the potential value of telehealth in the office practice and sports team setting. Telehealth may expand the ability of a sports medicine physician to provide timely and effective concussion care to athletes during the COVID-19 pandemic and beyond. More rigorous research is needed.

It's Time to Change Direction on Agility Research: a Call to Action.

Agility is an important skill for both attackers and defenders in invasion sports such as codes of football. On the sporting field, agility requires reacting to a stimulus, often presented by an opponent's movement, before a change of direction or speed. There is a plethora of research that examines the movement component of agility in isolation, which is described as change-of-direction (COD) ability, and this is thought to underpin agility performance. This opinion article proposes that COD ability should not be researched as the only or primary outcome measure when the objective is to inform agility performance in invasion sports. It is argued that pre-planned COD movements and tests lack ecological validity because they lack perception-action coupling and involve movement out of context from the game. The movement techniques and strength qualities required for the performance of COD tests can be quite different to those required for agility. It is suggested that COD tests can be applied to sports that involve pre-planned COD movements, but researchers should endeavour to use agility tests when studying invasion sports. Some new methods for assessing one-on-one agility contests are reported as potentially valuable for future research, and examples of research questions are provided.

Effect of Intention to Squat Explosively on Acute Countermovement Jump Performance.

ABSTRACT: O'Grady, MW, Young, WB, Behm, DG, and Talpey, SW. Effect of intention to squat explosively on acute countermovement jump performance. J Strength Cond Res 35(12): 3348-3354, 2021-The purpose of this study was to investigate the influence of squatting with the intention of moving the bar as fast as possible during the ascent phase on potentiating countermovement jump (CMJ) performance. Fourteen recreationally resistance-trained men (age = 22.1 ± 1.7 years, height = 179.9 ± 4.2 cm, body mass = 83.8 ± 6.6 kg) with a predicted 1 repetition maximum half-squat of 201.0 ± 27.8 kg participated in this study. Subjects performed 3 CMJs before and then 4 and 8 minutes after a squat conditioning activity (CA). Conditions were randomized. For 1 condition, the CA involved subjects performing 4 repetitions of the half-squat with a 5RM load in a controlled manner (CON) at a self-selected normal squatting tempo. In the other condition, subjects used the same number of repetitions and load; however, they were instructed to move the bar up as fast as possible during the concentric phase of the half-squat (VMAX). Half-squat peak force (N), peak power (W), peak velocity (m·s-1), and rate of force development (RFD) were measured for each CA using a force platform and linear position transducer. At 4 and 8 minutes post-CA, CMJ height, relative peak power, peak velocity, and peak force were also measured. Despite there being significant increases in the half-squat peak power, peak velocity and maximum RFD in the VMAX condition, neither condition significantly improved any post-CMJ variable. Some small improvements in jump height were observed in certain individuals after the VMAX condition, suggesting that an explosive half-squat CA may potentiate CMJ performance in certain individuals.

Sprinting and hamstring strain injury: Beliefs and practices of professional physical performance coaches in Australian football.

OBJECTIVES: The purpose of this study was to establish beliefs and practices of physical performance coaches regarding sprinting and Hamstring Strain Injury (HSI) in Australian Rules football. DESIGNS: Delphi-validated questionnaire. SETTING: Online. PARTICIPANTS: Eighteen high-performance managers of the Australian Football League. MAIN OUTCOME MEASURES: Descriptive statistics were collected to establish experience; central themes were established for the analyses of the beliefs and practices. RESULTS: Nine (50%) physical performance coaches responded to an invitation to complete the questionnaire. Participants held an undergraduate degree and had 9.2 ± 4.3 years of experience. Accelerations (n = 9), maximum speed sprints (n = 9) and running with hip flexion (n = 7) were the most common activities associated with HSI. Coaches believed sprinting, eccentric strength training and proper periodisation were effective strategies to reduce HSI risk. There's a disparity between beliefs and practices when using GPS to monitor sprinting, however, all coaches reported regular exposure to sprint training across both pre and in-season. Overstriding (n = 9) and pelvic instability (n = 6) were identified as key flaws in running mechanics. CONCLUSIONS: This information can be used to improve training strategies, whilst these findings indicate further investigations into sprint training and running mechanics for HSI risk reduction.

The Virtual Shoulder and Knee Physical Examination.

The COVID-19 crisis has forced a sudden and dramatic shift in the way that clinicians interact with their patients, from outpatient encounters to telehealth visits utilizing a variety of internet-based videoconferencing applications. Although many aspects of pre-COVID-19 outpatient sports medicine care will ultimately resume, it is likely that telehealth will persist because of its practicality and because of patient demand for access to efficient and convenient health care. Physical examination is widely considered a critical obstacle to a thorough evaluation of sports medicine patients during telehealth visits. However, a closer reflection suggests that a majority of the examination maneuvers are possible virtually with limited, if any, modifications. Thus, we provide a comprehensive shoulder and knee physical examination for sports medicine telehealth visits, including (1) verbal instructions in layman's terms that can be provided to the patient before or read verbatim during the visit, (2) multimedia options (narrated videos and annotated presentations) of the shoulder and knee examination that can be provided to patients via screen-share options, and (3) a corresponding checklist to aid in documentation.

Efficacy of Combined General, Special, and Specific Resistance Training on Pace Bowling Skill in Club-Standard Cricketers.

Feros, SA, Young, WB, and O'Brien, BJ. Efficacy of combined general, special, and specific resistance training on pace bowling skill in club-standard cricketers. J Strength Cond Res 34(9): 2596-2607, 2020-This study investigated the efficacy of combined "general," "special," and "specific" resistance training on pace bowling skill. Twelve male, club-standard pace bowlers were randomly allocated to a combined resistance training (CRT) program or traditional cricket training (TCT) program for 8 weeks. The CRT group (n = 6) trained with 300, 250-g, and standard cricket balls; performed 20-m sprints with +20% and +15% body mass resistance (but also unresisted); and completed chin-up and pull-up training. The TCT group (n = 6) trained with standard balls and performed unresisted 20-m sprints. No statistically significant GROUP × TIME interactions were identified. The CRT group demonstrated a "clear moderate" enhancement in peak ball release speed (mean ±95% confidence limits [CLs]: 1.2 ± 1.5 m·s, d = 0.66 ± 0.83), a "clear large" increase in mean radial error (mean ±95% CLs: 7.1 ± 6.5 cm, d = 0.94 ± 0.87), and a "clear large" rise in bivariate variable error (mean ±95% CLs: 7.2 ± 7.8 cm, d = 0.97 ± 1.05). The TCT group exhibited "unclear" changes across all pace bowling skill measures. Both groups displayed "unclear" changes in approach speed, 20-m sprint time, and 1 repetition maximum pull-up strength. In 8 weeks, the CRT program improved peak ball release speed, but at the cost of poorer bowling accuracy and consistency of bowling accuracy. These findings could be attributed to bowling with the heavier balls. The inclusion of "specific" resistance training does not seem to be effective in enhancing all-round pace bowling skill in club-standard cricketers.

The effects of sprint training and the Nordic hamstring exercise on eccentric hamstring strength and sprint performance in adolescent athletes.

BACKGROUND: Hamstring strain injuries (HSI) are among the most common injuries in field-based team sports with a high-speed running component. The implementation of the Nordic hamstring exercise (NHE) is a well-documented method of improving eccentric hamstring strength to mitigate the risk of HSI occurrence. Sprint training is specific to the injury mechanism and is thought to activate the hamstrings through maximal eccentric contractions. The purpose of this study was to compare the effects of sprint training and the NHE on eccentric hamstring strength and sprint performance. METHODS: Twenty-eight participants (mean±SD age=16.21±1.34 years; height=1.75m±0.10m; body mass=68.5kg±12.1kg) completed an eccentric hamstring strength assessment and 40m sprint to assess acceleration and maximum speed. Participants were randomly allocated to either a NHE training or sprint training group. Two sessions per week for four-weeks of training was performed with baseline testing procedures repeated in the week following the intervention. Perceptions of soreness were recorded following the warm-up in each training session. RESULTS: Both the NHE (effect size=0.39, P<0.05) and sprint training (effect size=0.29, P<0.05) groups displayed significant gains in eccentric hamstring strength. The NHE group reported trivial improvements in sprint performance, whilst the sprint training group experienced a moderate improvement, specifically in maximum speed (ES=0.83 Moderate). Sprint training also produced greater perceptions of soreness than the NHE following a four-week training intervention, specifically before the start of the last session (P<0.05). CONCLUSIONS: These findings indicate that sprint training had a beneficial effect for both eccentric hamstring strength and sprint performance, whilst also producing greater soreness than the NHE following the final training session. It was concluded that a four-week block of maximum speed training may have both an injury prevention and performance enhancement benefit.

Association Between Preseason Training and Performance in Elite Australian Football.

PURPOSE: To examine the association between preseason training variables and subsequent in-season performance in an elite Australian football team. METHODS: Data from 41 elite male Australian footballers (mean [SD] age = 23.4 [3.1] y, height =188.4 [7.1] cm, and mass = 86.7 [7.9] kg) were collected from 1 Australian Football League (AFL) club. Preseason training data (external load, internal load, fitness testing, and session participation) were collected across the 17-wk preseason phase (6 and 11 wk post-Christmas). Champion Data© Player Rank (CDPR), coaches' ratings, and round 1 selection were used as in-season performance measures. CDPR and coaches' ratings were examined over the entire season, first half of the season, and the first 4 games. Both Pearson and partial (controlling for AFL age) correlations were calculated to assess if any associations existed between preseason training variables and in-season performance measures. A median split was also employed to differentiate between higher- and lower-performing players for each performance measure. RESULTS: Preseason training activities appeared to have almost no association with performance measured across the entire season and the first half of the season. However, many preseason training variables were significantly linked with performance measured across the first 4 games. Preseason training variables that were measured post-Christmas were the most strongly associated with in-season performance measures. Specifically, total on-field session rating of perceived exertion post-Christmas, a measurement of internal load, displayed the greatest association with performance. CONCLUSION: Late preseason training (especially on-field match-specific training) is associated with better performance in the early season.

Relationship Between Selected Physical Qualities, Bowling Kinematics, and Pace Bowling Skill in Club-Standard Cricketers.

Feros, SA, Young, WB, and O'Brien, BJ. Relationship between selected physical qualities, bowling kinematics, and pace bowling skill in club-standard cricketers. J Strength Cond Res 33(10): 2812-2825, 2019-Although strength and conditioning of cricket pace bowlers has become more specialized in recent times, little is understood about the interplay between physical capacities, pace bowling kinematics, and pace bowling skill measures. This study sought to determine these interrelationships. Thirty-one male club-standard pace bowlers completed 3 test sessions on separate occasions 4-7 days apart. The first testing session comprised an 8-over pace bowling assessment, where bowling skill and selected bowling kinematics were measured. A physical test battery was completed over the remaining 2 sessions. Peak and mean ball release (BR) speed were related with 1 repetition maximum pull-up strength (rs = 0.56, p = 0.005) and correlated with 20-m sprint time (rs = -0.42, p = 0.022; rs = -0.37, p = 0.044, respectively). Mean radial error was associated with 10-m and 20-m sprint times (rs = 0.41, p = 0.030; rs = 0.38, p = 0.037, respectively), and correlated with height and peak power from 3 countermovement jumps (CMJs) (rs = -0.39, p = 0.036; rs = -0.41, p = 0.031, respectively), and mean peak power from 20 CMJs (rs = -0.45, p = 0.020). Bivariate variable error was correlated with front-leg extension angle at BR (rs = 0.41, p = 0.036), and also with approach speed (rs = -0.36, p = 0.050). These relationships may assist strength and conditioning coaches in designing more effective training programs to enhance bowling speed and accuracy. Training interventions are warranted, however, to validate these associations.

Gradual vs. Maximal Acceleration: Their Influence on the Prescription of Maximal Speed Sprinting in Team Sport Athletes.

The primary purpose of this study was to determine if a difference existed between peak speed attained when performing a sprint with maximal acceleration versus from a gradual build-up. Additionally, this investigation sought to compare the actual peak speed achieved when instructed to reach 75% and 90% of maximum speed. Field sport athletes (n = 21) performed sprints over 60 m under the experimental conditions, and the peak speed was assessed with a radar gun. The gradual build-up to maximum speed (8.30 ± 0.40 m∙s-1) produced the greater peak speed (effect size = 0.3, small) than the maximum acceleration run (8.18 ± 0.40 m∙s-1), and the majority of participants (62%) followed this pattern. For the sub-maximum runs, the actual mean percentage of maximum speed reached was 78 ± 6% for the 75% prescribed run and 89 ± 5% for the 90% prescription. The errors in attaining the prescribed peak speeds were large (~15%) for certain individuals, especially for the 75% trial. Sprint training for maximum speed should be performed with a gradual build-up of speed rather than a maximum acceleration. For sub-maximum interval training, the ability to attain the prescribed target peak speed can be challenging for field sport athletes, and therefore where possible, feedback on peak speeds reached should be provided after each repetition.

Association Between Pre-season Training and Performance in Elite Australian Football.

PURPOSE: To examine the association between pre-season training variables and subsequent in-season performance in an elite Australian football team. METHODS: Data from forty-one elite male Australian footballers (mean±SD: age=23.4±3.1y; height=188.4±7.1cm; mass=86.7±7.9kg) was collected from one Australian Football League (AFL) club. Pre-season training data (external load, internal load, fitness testing and session participation) were collected across the 17-week pre-season phase (6-weeks pre-Christmas, 11-weeks post-Christmas). Champion Data© Player Rank (CDPR), coaches' ratings (CR) and round one selection were used as in-season performance measures. CDPR and CR were examined over the entire season, first half of the season and the first four games. Both Pearson and partial (controlling for AFL age) correlations were calculated to assess if any associations existed between pre-season training variables and in-season performance measures. A median-split was also employed to differentiate between higher and lower performing players for each performance measure. RESULTS: Pre-season training activities appeared to have almost no association with performance measured across the entire season and the first half of the season. However, many pre-season training variables were significantly linked with performance measured across the first four games. Pre-season training variables that were measured post-Christmas were the most strongly associated with in-season performance measures. Specifically, Total on-field session rating of perceived exertion (sRPE) post-Xmas, a measurement of internal load, displayed the greatest association with performance. CONCLUSIONS: Late pre-season training (especially on-field match specific training) is associated with better performance in the early season.

Quantifying Cricket Fast-Bowling Skill.

OBJECTIVES: To evaluate the current evidence regarding the quantification of cricket fast-bowling skill. METHODS: Studies that assessed fast-bowling skill (bowling speed and accuracy) were identified from searches in SPORTDiscus (EBSCO) in June 2017. The reference lists of identified papers were also examined for relevant investigations. RESULTS: A total of 16 papers matched the inclusion criteria, and discrepancies in assessment procedures were evident. Differences in test environment, pitch, and cricket ball characteristics; the warm-up prior to test; test familiarization procedures; permitted run-up lengths; bowling spell length; delivery sequence; test instructions; collection of bowling speed data; and collection and reportage of bowling accuracy data were apparent throughout the literature. The reliability and sensitivity of fast-bowling skill measures have rarely been reported across the literature. Only 1 study has attempted to assess the construct validity of its skill measures. CONCLUSIONS: There are several discrepancies in how fast-bowling skill has been assessed and subsequently quantified in the literature to date. This is a problem, because comparisons between studies are often difficult. Therefore, a strong rationale exists for the creation of match-specific standardized fast-bowling assessments that offer greater ecological validity while maintaining acceptable reliability and sensitivity of the skill measures. If prospective research can act on the proposed recommendations from this review, then coaches will be able to make more informed decisions surrounding player selection, talent identification, return to skill following injury, and the efficacy of short- and long-term training interventions for fast bowlers.

The Reliability and Sensitivity of Performance Measures in a Novel Pace-Bowling Test.

OBJECTIVES: To evaluate the reliability and sensitivity of performance measures in a novel pace-bowling test. METHODS: Thirteen male amateur-club fast bowlers completed a novel pace-bowling test on 2 separate occasions, 4-7 d apart. Participants delivered 48 balls (8 overs) at 5 targets on a suspended sheet situated behind a live batter, who stood in a right-handed and left-handed stance for an equal number of deliveries. Delivery instruction was frequently changed, with all deliveries executed in a preplanned sequence. Data on ball-release speed were captured by radar gun. A high-speed camera captured the moment of ball impact on the target sheet for assessment of radial error and bivariate variable error. Delivery rating of perceived exertion (0-100%) was collected as a measure of intensity. RESULTS: Intraclass correlation coefficients and coefficients of variation revealed excellent reliability for peak and mean ball-release speed, acceptable reliability for delivery rating of perceived exertion, and poor reliability for mean radial error, bivariate variable error, and variability of ball-release speed. The smallest worthwhile change indicated high sensitivity with peak and mean ball-release speed and lower sensitivity with mean radial error and bivariate variable error. CONCLUSIONS: The novel pace-bowling test incorporates improvements in ecological validity compared with its predecessors and can be used to provide a more comprehensive evaluation of pace-bowling performance. Data on the smallest worthwhile change can improve interpretation of pace-bowling research findings and may therefore influence recommendations for applied practice.

Reliability of a Field Test of Defending and Attacking Agility in Australian Football and Relationships to Reactive Strength.

Young, WB and Murray, MP. Reliability of a field test of defending and attacking agility in Australian football and relationships to reactive strength. J Strength Cond Res 31(2): 509-516, 2017-Defending and attacking agility tests for Australian football do not exist, and it is unknown whether any physical qualities correlate with these types of agility. The purposes of this study were to develop new field tests of defending and attacking agility for Australian Rules football, to determine whether they were reliable, and to describe the relationship between the agility tests to determine their specificity. Because the reactive strength (RS) of the lower limb muscles has been previously correlated with change-of-direction speed, we also investigated the relationship between this quality and the agility tests. Nineteen male competitive recreational-level Australian Rules football players were assessed on the agility tests and a drop jump test to assess RS. Interday and interrater reliability was also assessed. The agility tests involved performing 10 trials of one-on-one agility tasks against 2 testers (opponents), in which the objective was to be in a position to tackle (defending) or to evade (attacking) the opponent. Both agility tests had good reliability (intraclass correlation > 0.8, %CV < 3, and no significant differences between test occasions [p > 0.05], and interrater reliability was very high [r = 0.997, p < 0.001]). The common variance between the agility tests was 45%, indicating that they represented relatively independent skills. There was a large correlation between RS and defending agility (r = 0.625, p = 0.004), and a very large correlation with attacking agility (r = 0.731, p < 0.001). Defending and attacking agility have different characteristics, possibly related to the footwork, physical, and cognitive demands of each. Nonetheless, RS seems to be important for agility, especially for attacking agility.