Contact Breast Injuries Among Female Athletes: A Systematic Review

BACKGROUND

Robust surveillance of injury aetiology and epidemiology is recognised as fundamental for effective injury reduction and management programmes. However, while sex-specific differences in injury type and nature are noted in the literature, it is unclear if these are reflected in surveillance practices, and how the athlete is affected.

OBJECTIVE

Therefore, this study aimed to systematically review contact breast injuries (CBIs) among adult female athletes.

METHODS

The following databases were searched: PubMed, EMBASE, SPORTDiscus including MEDLINE, Web of Science and Scopus. The literature search was conducted in May 2023 and the search was limited to articles in the English and German language. Studies including female athletes, aged 18 years and above, in any sports (team or individual) at any level (amateur, semi-professional and professional), where an occurrence of CBI was documented were included. Studies were included irrespective of their investigated timeframes (e.g. the whole career, one or multiple seasons). Findings were categorised (e.g. sport, level of competition and investigated timeframe of the study) to enable possible comparisons. Case studies were excluded due to the non-generalisability of findings.

RESULTS

Of the six studies included, rugby codes (rugby union, rugby league and rugby sevens) had the highest occurrence rate (62.0%) of CBIs among eight different investigated sports (rugby codes 62.0%, softball 59.5%, Australian Football League (AFL) 51.0%, water polo 50.0%, soccer 46.7%, basketball 27.6-48.8%, volleyball 34.6%, boxing 0.0%). Between 25.6% and 62.0% of participants reported incurring a CBI and between 0.0% and 42.9% of CBIs were reported to a medical professional or support staff. The reported treatment rate for CBIs ranged between 0.0% and 2.1%, The main mechanisms for CBIs (where reported) were contact with another athlete (AFL 37.6%, rugby codes 56%) the ball (AFL 31.6%, rugby codes 25.5%) and the ground (AFL 6.6%, rugby codes 22%). Between 18.2% and 48% of the participants reported that CBIs negatively affected their performance. Risk factors increasing CBIs were positional differences, larger breast size and higher body mass index (BMI). In-season injury data collection and surveillance supported through education of both players and medical staff were identified to be of relevance for future CBI prevention. None of the studies reported incidence rate.

CONCLUSION

Despite the frequent occurrence of CBIs among female athletes, reporting and treatment remains low. Awareness and education of all stakeholders are fundamental to ensuring better breast safety in female sport. Identifying the mechanics, severity and risk factors of CBIs through thorough injury surveillance must be a focus of further research.

REGISTRATION

The study was preregistered on Open Science Framework (OSF).

Coaches of youth field sports as delivery agents of injury prevention programmes: how are we training the trainers? A scoping review

OBJECTIVE

To systematically map the coach education (CE) component of injury prevention programmes (IPPs) for youth field sports by identifying and synthesising the design, content and facilitation strategies used to address competency drivers and behaviour change.

DESIGN

Scoping review.

DATA SOURCES

PubMed, PsycInfo, EMBASE, CINAHL, SportDiscus and Google Scholar electronic databases were searched using keywords related to IPPs and youth field sports.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies of IPPs in youth field sports, that provided 'train-the-trainer' education to coaches as designated delivery agents.

RESULTS

20 studies from two field sports (soccer/football; n=17, Rugby Union; n=3) fulfilled the eligibility criteria. Eleven CE interventions occurred in the preseason and 18 occurred at one time-point (single day). Five studies cited use of a behavioural change theory or model in the design of their CE, most frequently the Health Action Process Approach model (n=5); and use of behavioural change techniques varied. Twelve of twenty studies (60%) reported some form of ongoing support to coaches following the CE primary intervention concurrent with IPP implementation.

CONCLUSION

CE that occurs on 1 day (one time-point) is most popular for preparing coaches as delivery agents of IPPs in youth field sports. While recognising pragmatic barriers, more expansive in-service training, support and feedback may enhance the effective implementation of IPPs.

TRIAL REGISTRATION NUMBER

https://doi.org/10.17605/OSF.IO/FMHGD.

Injury Trends for School Rugby Union in Ireland: The Need for Position-specific Injury-prevention Programs

BACKGROUND

Concern has been raised over the injury risk to school Rugby union (Rugby) players and the potential long-term health consequences. Despite the increase in studies for this cohort, the influence of playing position on injury incidence and presentation is unclear.

PURPOSE

To describe the incidence, nature and severity of match injuries for school Rugby in Ireland overall, and as a function of playing position.

STUDY DESIGN

Prospective cohort study.

METHODS

Data were collected from 15 male (aged 16-19 years) school Senior Cup teams across 2 seasons. In total, 339 players participated in season 1, whereas 326 players participated in season 2. Injury data were recorded onto a bespoke online platform. Match exposure was also recorded.

RESULTS

The incidence rate of match injuries (24-hour time loss) was 53.6 per 1000 hours. Across both seasons, 6810 days were lost from play due to injury. Forwards (65.4 per 1000 hours) sustained significantly more (P < 0.05) injuries than backs (40.5 per 1000 hours). The head, shoulder, knee, and ankle were the most common injured body regions; however, forwards sustained significantly more (P < 0.05) head and shoulder injuries than backs. The tackle was responsible for the majority of injuries in both groups. The highest proportion of injuries occurred during the third quarter.

CONCLUSION

Clear differences in injury presentation and incidence were evident when comparing forwards versus backs. The high rate of head and shoulder injuries in the forwards suggest the need for more targeted injury-prevention strategies and further research on education and laws around the tackle event. The spike of injuries in the third quarter suggests that fatigue or inadequate half-time warm-up may be a contributing factor warranting further exploration.

CLINICAL RELEVANCE

This study demonstrates clear differences in injury presentation according to playing position in school Rugby and highlights the need for a more tailored approach to the design and implementation of injury-prevention strategies.

LEVEL OF EVIDENCE

Level 3.

Profiling elite male 100-m sprint performance: The role of maximum velocity and relative acceleration

PURPOSE

This study aimed to determine the accuracy of a 4 split time modelling method to generate velocity-time and velocity-distance variables in elite male 100-m sprinters and subsequently to assess the roles of key sprint parameters with respect to 100-m sprint performance. Additionally, this study aimed to assess the differences between faster and slower sprinters in key sprint variables that have not been assessed in previous work.

METHODS

Velocity-time and velocity-distance curves were generated using a mono-exponential function from 4 split times for 82 male sprinters during major athletics competitions. Key race variables-maximum velocity, the acceleration time constant (τ), and percentage of velocity lost (v_Loss)-were derived for each athlete. Athletes were divided into tertiles, based on 100-m time, with the first and third tertiles considered to be the faster and slower groups, respectively, to facilitate further analysis.

RESULTS

Modelled split times and velocities displayed excellent accuracy and close agreement with raw measures (range of mean bias was -0.2% to 0.2%, and range of intraclass correlation coefficients (ICCs) was 0.935 to 0.999) except for 10-m time (mean bias was 1.6% ± 1.3%, and the ICC was 0.600). The 100-m sprint performance time and all 20-m split times had a significant near-perfect negative correlation with maximum velocity (r ≥ -0.90) except for the 0 to 20-m split time, where a significantly large negative correlation was found (r = -0.57). The faster group had a significantly higher maximum velocity and τ (p < 0.001), and no significant difference was found for v_Loss (p = 0.085).

CONCLUSION

Coaches and researchers are encouraged to utilize the 4 split time method proposed in the current study to assess several key race variables that describe a sprinter's performance capacities, which can be subsequently used to further inform training.

A blood biomarker and clinical correlation cohort study protocol to diagnose sports-related concussion and monitor recovery in elite rugby

Introduction

In professional rugby, sports-related concussion (SRC) remains the most frequent time loss injury. Therefore, accurately diagnosing SRC and monitoring player recovery, through a multi-modal assessment process, is critical to SRC management. In this protocol study, we aim to assess SRC over multiple time points post-injury to determine the value of multi-modal assessments to monitor player recovery. This is of significance to minimise premature return-to-play and, ultimately, to reduce the long-term effects associated with SRC. The study will also establish the logistics of implementing such a study in a professional setting to monitor a player's SRC recovery.

Methods and analysis

All players from the participating professional rugby club within the Irish Rugby Football Union are invited to participate in the current study. Player assessment includes head injury assessment (HIA), neuropsychometric assessment (ImPACT), targeted biomarker analysis and untargeted biomarker analysis. Baseline HIA, ImPACT, and blood draws are performed prior to the start of playing season. During the baseline tests, player's complete consent forms and an SRC history questionnaire. Subsequently, any participant that enters the HIA process over the playing season due to a suspected SRC will be clinically assessed (HIA and ImPACT) and their blood will be drawn within 3 days of injury, 6 days post-injury, and 13 days post-injury.

Ethics and dissemination

Ethical approval was attained from the Science and Engineering Research Ethics Committee, University of Limerick (Approval Code: 2018_06_11_S&E). On completion of the study, further manuscripts will be published to present the results of the tests and their ability to measure player recovery from SRC.

Trial registration number

NCT04485494.

Epidemiology of Shoulder Injuries in Schoolboy Rugby Union in Ireland

BACKGROUND

The shoulder has been reported as a frequent location of injury in adult professional and amateur rugby, with match injury incidence rates ranging from 1.8 to 3 per 1000 player-hours (h). An increased understanding of the incidence and mechanism of shoulder injuries in school rugby players is vital to establish effective injury preventive strategies and advise on appropriate rehabilitation.

PURPOSE

To describe the incidence, nature, and severity of shoulder injuries in schoolboy rugby in Ireland.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Injury surveillance was carried out for Senior Cup teams across two seasons (N = 665 players aged 17-19 years) in Ireland from 2018 to 2020. Match and training injury data were recorded using an online system by trained nominated injury recorders. Match exposure was also recorded.

RESULTS

Shoulder match injury incidence was 12.2 per 1000 h (95% CI, 9.1-16.2), with a mean severity of 47 days' time loss and an overall burden of 573 days per 1000 h. In total, 47 match and 5 training shoulder injuries were recorded. The most common injuries were shoulder dislocations/subluxations (34%), followed by acromioclavicular joint sprains (30%). Shoulder dislocations/subluxations represented the most burdensome injury (280 days per 1000 h). The tackle accounted for the majority (81%) of shoulder injuries. Forwards sustained a significantly higher incidence of shoulder injuries (8.3/1000 h) in comparison with backs (3.9/1000 h), with a rate ratio of 2.13 (95% CI, 1.15-3.94; P = .015).

CONCLUSION

We found a notably higher injury incidence rate in schoolboy rugby as compared with the adult amateur and professional game. Shoulder injuries were responsible for more days lost than any other injury, and shoulder dislocations were the most severe. This is of particular concern so early in a player's career and warrants further investigation into potential risk factors and mechanisms associated with shoulder injuries in school-age players.

Resistance Training Practices of Sprint Coaches

ABSTRACT

Healy, R, Kenny, IC, and Harrison, AJ. Resistance training practices of sprint coaches. J Strength Cond Res 35(7): 1939-1948, 2021-This study describes the results of a survey of resistance training practices of sprint coaches. This study investigated why sprint coaches prescribe resistance training to their athletes, what exercises they select, and what factors are involved with their selection. Forty-one of 73 (56%) sprint coaches with mean ± SD coaching experience of 8.4 ± 6.4 years were included in this study. Coaches completed an online questionnaire consisting of 5 sections: (a) informed consent, (b) coach background information, (c) coach education and qualifications, (d) coaches' views on resistance training, and (e) exercise selection and preference. The results showed that coaches prescribe resistance training to their sprint athletes to develop strength and power, which they believe will transfer to sprint performance. Coaches prescribed a wide variety of traditional, ballistic, and plyometric exercises, with the hurdle jump found to be the most widely prescribed exercise (93% of coaches surveyed). Coaches selected exercises for a variety of reasons; however, the 3 most prominent reasons were: (a) performance adaptations; (b) practicality; and (c) the targeting of muscles/muscle groups. Coaches prioritized exercises that specifically developed strength, power, and reactive strength for their sprint athletes. This research can be used to develop educational resources for sprint coaches who wish to use resistance training with their athletes. In addition, sprint coaches can use the data presented to expand their current exercise repertoire and resistance training practices.

Training Load Monitoring in Amateur Rugby Union: A Survey of Current Practices

ABSTRACT

Griffin, A, Kenny, IC, Comyns, TM, and Lyons, M. Training load monitoring in amateur Rugby Union: A survey of current practices. J Strength Cond Res 35(6): 1568-1575, 2021-Amateur Rugby Union has an inherent risk of injury that is associated with detrimental effects on player welfare and team performance. Training load (TL) is a modifiable risk factor that, when monitored, may provide strength and conditioning (S&C) coaches with opportunities to reduce the risk of injury. The purpose of this study was to explore TL monitoring practices used by S&C coaches working with male and female amateur adult Rugby Union teams and their rationale for using such. Thirty-three (n = 31 male and n = 2 female) S&C coaches representing 62% of the total number of male clubs and 71% of female clubs, playing at the highest national amateur level, participated in the study by completing an online survey. Seventy-three percent of respondents stated that they monitor TL. The most common method of recording TL was the session rating of perceived exertion (sRPE), used in 83% of monitoring systems. Thirty-three percent of the S&C coaches surveyed use the sRPE data to calculate the acute:chronic workload ratio (ACWR) for highlighting when players are at risk of injury. This study is the first of its kind to exclusively examine the TL monitoring practices of S&C coaches working with amateur adult Rugby Union teams. Thirteen S&C coaches responded to the open-ended question and 3 higher order themes were highlighted: (a) communication with players (b) support from other staff and (c) limiting factors.

Training load monitoring in team sports: a practical approach to addressing missing data

Training load (TL) is a modifiable risk factor that may provide practitioners with opportunities to mitigate injury risk and increase sports performance. A regular problem encountered by practitioners, however, is the issue of missing TL data. The purpose of this study was to examine the impact of missing TL data in team sports and to offer a practical and effective method of missing value imputation (MVI) to address this. Session rating of perceived exertion (sRPE) data from 10 male professional soccer players (age, 24.8 ± 5.0 years; height, 181.2 ± 5.1 cm; mass, 78.7 ± 6.4 kg) were collected over a 32-week season. Data were randomly removed at a range of 5-50% in increments of 5% and data were imputed using 12 MVI methods. Performance was measured using the normalized root-mean-square error and mean of absolute deviations. The best-fitting MVI method across all levels of missingness was Daily Team Mean (DTMean). Not addressing missing sRPE data may lead to more inaccurate calculations of other TL metrics (e.g., acute chronic workload ratio, training monotony, training strain). The DTMean MVI method may provide practitioners with a practical and effective approach to addressing the negative consequences of missing TL data.

Injury Trends in Irish Amateur Rugby: An Epidemiological Comparison of Men and Women

Background:

Rugby union is a physically demanding sport that carries an inherent risk of injury. Despite being a popular and widely played team sport, little is known about injuries occurring across the male and female amateur game.

Purpose:

To establish and compare injury incidence, nature, and severity in male and female Irish amateur rugby union.

Study Design:

Prospective cohort study.

Level of Evidence:

Level 3.

Methods:

Data were collected prospectively from 25 male teams (959 players) and 8 female teams (234 players) over 2 full seasons. Both time-loss (24-hour time-loss injury definition) and non-time-loss match injury reports were collected, alongside match exposure data.

Results:

Time-loss match injury incidence rates were 49.1/1000 and 35.6/1000 player-hours for male and female players, respectively. Concussion and ankle ligament sprains were the most common diagnoses for male (5.6/1000 and 4.4/1000 player-hours, respectively) and female players (5.5/1000 and 3.9/1000 player-hours, respectively). Anterior cruciate ligament injuries presented the highest injury burden for male and female players with 200.3 and 307.2 days of absence per 1000 player-hours, respectively. In female players, 83% of noncontact injuries occurred in the fourth quarter of match play.

Conclusion:

While female players had a lower overall injury incidence rate compared with male players, concussion and ankle ligament injuries were the most common injuries in both cohorts. In female players, a high rate of noncontact injuries in the second half points to the need for strength and conditioning training programs to reduce fatigue-related injuries.

Clinical Relevance:

Establishing the incidence and burden of rugby-related injuries is an essential step in minimizing injury risk. This epidemiological information will aid the development of future reduction strategies, including education and coaching strategies and strength and conditioning programs, informed by the most common injuries observed and the mechanism of injury.

Injury surveillance and prevention practices across Rugby schools in Ireland

OBJECTIVES

To ascertain the extent of injury surveillance and prevention practices currently in operation and the availability of qualified personnel across Rugby playing schools in the Republic of Ireland.

DESIGN

Cross-sectional survey design.

SETTING

Rugby playing schools across Ireland.

PARTICIPANTS

The Rugby games master, head Rugby coach or teacher/coach with knowledge of all Rugby activities in the school.

RESULTS

Ninety-three Rugby playing schools responded and reported 356 (97% male, 3% female) school Rugby teams. Rugby injuries were formally monitored in 86% of schools. Injury recorders were primarily coaches (61%). Physiotherapy provision was available in 28% of schools, 14% of schools provided access to a medical doctor and 44% of schools provided access to an S&C coach. Structured warm-ups were undertaken in 66% of schools, weekly gym sessions in 49% of schools and 31% of schools did not implement any formal injury prevention measures.

CONCLUSIONS

Injury monitoring practices, medical personnel accessibility and the frequency of injury prevention practices varies considerably across Rugby playing schools in Ireland. Future injury surveillance and prevention systems should be suitable for use by non-medical personnel and reflect the structural organisation of the school Rugby game so that data are not solely representative of the elite, well-resourced schools.

Influence of Reactive and Maximum Strength Indicators on Sprint Performance

Healy, R, Smyth, C, Kenny, IC, and Harrison, AJ. Influence of reactive and maximum strength indicators on sprint performance. J Strength Cond Res 33(11): 3039-3048, 2019-The primary aim of this study was to assess the relationship between reactive and maximal strength measures with 40 m sprint performance and mechanical properties. Fourteen male and 14 female sprinters participated in this study. On the first day, subjects performed 40 m sprints with 10-m split times recorded in addition to maximal theoretical velocity, maximal theoretical force and peak horizontal power, which were calculated from force-velocity relationships. On the second day, subjects performed isometric midthigh pulls (IMTPs) with peak force (PF) and relative PF calculated, drop jumps (DJs) and vertical hopping where the reactive strength index (RSI) was calculated as jump height (JH) divided by contact time (CT). Pearson correlations were used to assess the relationships between measures and independent samples t-tests were used to assess the differences between men and women. No significant correlations were found between DJ and hopping RSI and sprint measures. A significant strong positive correlation was found between IMTP PF and peak horizontal power in men only (r = 0.61). The male sprinters performed significantly better in all recorded measures apart from hopping (CT, JH and RSI) and DJ CT where no significant differences were found. The lack of association between reactive and maximal strength measures with sprint performance is potentially because of the test's prolonged CTs relative to sprinting and the inability to assess the technical application of force. Several methods of assessing reactive strength are needed that can better represent the demands of the distinct phases of sprinting e.g., acceleration, maximum velocity.

The design, development, implementation and evaluation of IRISweb; A rugby-specific web-based injury surveillance system

OBJECTIVES

To describe the development, implementation and evaluation of a comprehensive injury surveillance system.

DESIGN

The four phases; i) A survey of 58 medical professionals working in amateur rugby. ii) The design of a web-based injury surveillance system (IRISweb). iii) Recruitment of 21 of the top 58 amateur clubs to use IRISweb. iv) An evaluation survey of the 21 participating clubs.

SETTING

Irish amateur rugby clubs.

PARTICIPANTS

Medical professionals working in amateur rugby.

MAIN OUTCOME MEASURES

Phase one investigated the injury monitoring practices in operation prior to the IRIS project. Phase four investigated the effectiveness and usefulness of IRISweb.

RESULTS

Twenty-one clubs were recruited, however 2 clubs failed to provide a full season of data (10% dropout rate). Eighty-two percent of the remaining 19 clubs rated IRISweb as 'good' or 'very good'. Facilitators of injury surveillance were; increased player adherence (65%) and notifications to update the system (59%), however, poor player adherence (71%) and medical staff availability (24%) were the main barriers.

CONCLUSIONS

The IRIS project is the first prospective long-term injury surveillance system in Irish amateur rugby, effectively tracking injuries to guide future evidence-based injury prevention strategies. This study highlights facilitators and barriers to injury surveillance within amateur sport.

The Effect of Strength Training on Performance Indicators in Distance Runners

Beattie, K, Carson, BP, Lyons, M, Rossiter, A, and Kenny, IC. The effect of strength training on performance indicators in distance runners. J Strength Cond Res 31(1): 9-23, 2017-Running economy (RE) and velocity at maximal oxygen uptake (VV[Combining Dot Above]O2max) are considered to be the best physiological performance indicators in elite distance runners. In addition to cardiovascular function, RE and VV[Combining Dot Above]O2max are partly dictated by neuromuscular factors. One technique to improve neuromuscular function in athletes is through strength training. The aim of this study was to investigate the effect of a 40-week strength training intervention on strength (maximal and reactive strength), VV[Combining Dot Above]O2max, economy, and body composition (body mass, fat, and lean mass) in competitive distance runners. Twenty competitive distance runners were divided into an intervention group (n = 11; 29.5 ± 10.0 years; 72.8 ± 6.6 kg; 1.83 ± 0.08 m) and a control group (n = 9; 27.4 ± 7.2 years; 70.2 ± 6.4 kg; 1.77 ± 0.04 m). During week 0, 20, and 40, each subject completed 3 assessments: physiology (V2 mmol·L BLa, V2 mmol·L BLa [blood lactate], V4 mmol·L BLa, RE, VV[Combining Dot Above]O2max, V[Combining Dot Above]O2max), strength (1 repetition maximum back squat; countermovement jump and 0.3 m drop jump), and body composition (body mass, fat mass, overall lean, and leg lean). The intervention group showed significant improvements in maximal and reactive strength qualities, RE, and VV[Combining Dot Above]O2max, at weeks 20 (p ≤ 0.05) and 40 (p ≤ 0.05). The control group showed no significant changes at either time point. There were no significant changes in body composition variables between or within groups. This study demonstrates that 40 weeks of strength training can significantly improve maximal and reactive strength qualities, RE, and VV[Combining Dot Above]O2max, without concomitant hypertrophy, in competitive distance runners.

Assessing Reactive Strength Measures in Jumping and Hopping Using the Optojump™ System

The aim of this study was to assess the concurrent validity of the Optojump™ system (Microgate, Bolzano, Italy) versus a force platform in the estimation of temporal and reactive strength measures. In two separate investigations, twenty physically active males performed double-leg and single-leg drop jumps from a box height of 0.3 m and a 10 s vertical bilateral hopping test. Contact time, flight time and total time (the sum of contact and flight time) were concurrently assessed during single and double-leg drop jumps and during hopping. Jump height, the reactive strength index and the reactive strength ratio were also calculated from contact time and flight time. Despite intraclass correlation coefficients (ICCs) for all variables being close to 1 (ICC > 0.975), a significant overestimation was found in contact time (0.005 ± 0.002 s) and underestimations in flight time (0.005 ± 0.003 s), the reactive strength index (0.04 ± 0.02 m·s-1) and the reactive strength ratio (0.07 ± 0.04). Overestimations in contact time and underestimations in flight time were attributed to the physical design of the Optojump™ system as the transmitter and receiver units were positioned 0.003 m above the floor level. The Optojump™ demonstrated excellent overall temporal validity with no differences found between systems for total time. Coaches are advised to be consistent with the instrumentation used to assess athletes, however, in the case of comparison between reactive strength values collected with the Optojump™ and values collected with a force platform, regression equations are provided.

Validation of an electronic jump mat to assess stretch-shortening cycle function

The purpose of this investigation was to determine the concurrent validity of a commonly used electronic switch mat (ESM), or jump mat, compared with force plate (FP) data. The efficiency of collection and accuracy of data are paramount to athlete and player field testing for the strength and conditioning coach who often has access only to a jump mat. Ten subjects from 5 different sporting backgrounds completed 3 squat jumps (SJs), 3 countermovement jumps (CMJs), and 3 drop jumps (DJs). The jumps were performed on an AMTI FP operating at 1,000 Hz with an ESM positioned on top of the platform. All the subjects were experienced with the protocols involved with jump testing. The resulting absolute errors between FP and ESM data were 0.01, 0.02, and 0.01 m for CMJ, SJ, and DJ heights, respectively. However, the coefficient of variation for the DJ contact time (CT) was 57.25%, CMJ (r = 0.996), and SJ (r = 0.958) heights correlated very strongly with force platform data, and DJ data were not as strong (r = 0.683). Confidence interval tests revealed bias toward CMJ and SJ (p < 0.05). The jump mat can accurately calculate the CMJ height, SJ height, and reactive strength index for all the 3 jump protocols. However, the faster CTs and rapid movements involved in a DJ may limit its reliability when giving measures of CT, flight time, and height jumped for DJs. Strength and conditioning coaches can use such a jump mat device with the confidence that it is accurately producing valid measurements of their athlete's performance for CMJ and SJ slow SSC protocols.