Paul J. Read

The scientific foundations and associated injury risks of early soccer specialisation

ABSTRACT Early specialisation is characterised by formal participation in a single sport at the exclusion of others. Limited data are available to support this approach in the development of soccer players who attain elite status later in life. Of growing concern is the associated increased risk of injury and suggestions that single sport specialisation is a risk factor independent of age, growth, biological maturation and training volumes. In the United Kingdom, elite soccer organisations have recently adopted an early sport specialisation approach following the introduction of the Elite Player Performance Plan. A key tenet of this programme is increased opportunities for training through a marked rise in the specified on-pitch hours per week. The accumulation of high training hours may be less of a relevant marker for success, and the impact of such a significant increase in training volume for young athletes who are experiencing a range of growth and maturational processes is currently unknown. This critical commentary includes an evidence-based discussion of the effectiveness of early sport specialisation and the potential injury risks associated with such programmes placing a specific focus on elite male youth soccer players. Available data indicate that modifications to the existing Elite Player Performance Plan framework could enhance players’ development and reduce injury risk. Proposed alterations include reduced volume of soccer-specific training at key stages of growth and maturation and guidelines for the provision of a greater variety of physical activities that are integrated within other programme components.

Relationships Between Field-Based Measures of Strength and Power and Golf Club Head Speed

Abstract Read, PJ, Lloyd, RS, De Ste Croix, M, and Oliver, JL. Relationships between field-based measures of strength and power and golf club head speed. J Strength Cond Res 27(10): 2708–2713, 2013—Increased golf club head speed (CHS) has been shown to result in greater driving distances and is also correlated with golf handicap. The purpose of this study was to investigate the relationships between field-based measures of strength and power and golf CHS with a secondary aim to determine the reliability of the selected tests. A correlation design was used to assess the following variables: anthropometrics, squat jump (SJ) height and squat jump peak power (SJPP), unilateral countermovement jump (CMJ) heights (right leg countermovement jump and left leg countermovement jump [LLCMJ]), bilateral CMJ heights, countermovement jump peak power (CMJPP), and medicine ball seated throw (MBST) and medicine ball rotational throw (MBRT). Fouty-eight male subjects participated in the study (age: 20.1 ± 3.2 years, height: 1.76 ± 0.07 m, mass: 72.8 ± 7.8 kg, handicap: 5.8 ± 2.2). Moderate significant correlations were reported between CHS and MBRT (r = 0.67; p < 0.01), MBST (r = 0.63; p < 0.01), CMJPP (r = 0.54; p < 0.01), and SJPP (r = 0.53; p < 0.01). Weak significant correlations (r = 0.3–0.5) were identified between CHS and the other remaining variables excluding LLCMJ. Stepwise multiple regression analysis identified that the MBST and SJ were the greatest predictors of CHS, explaining 49% of the variance. Additionally the intraclass correlation coefficients reported for tests of CHS and all performance variables were deemed acceptable (r = 0.7–0.9). The results of this study suggest that the strength and conditioning coach can accurately assess and monitor the physical abilities of golf athletes using the proposed battery of field tests. Additionally, movements that are more concentrically dominant in nature may display stronger relationships with CHS due to MBST and SJ displaying the highest explained variance after a stepwise linear regression.

Neuromuscular Risk Factors for Knee and Ankle Ligament Injuries in Male Youth Soccer Players

Injuries reported in male youth soccer players most commonly occur in the lower extremities, and include a high proportion of ligament sprains at the ankle and knee with a lower proportion of overuse injuries. There is currently a paucity of available literature that examines age- and sex-specific injury risk factors for such injuries within youth soccer players. Epidemiological data have reported movements that lead to non-contact ligament injury include running, twisting and turning, over-reaching and landing. Altered neuromuscular control during these actions has been suggested as a key mechanism in females and adult populations; however, data available in male soccer players is sparse. The focus of this article is to review the available literature and elucidate prevalent risk factors pertaining to male youth soccer players which may contribute to their relative risk of injury.

Lower extremity stiffness: effects on performance and injury and implications for training

ABSTRACT THIS ARTICLE REVIEWS RESEARCH TO DATE ON LOWER EXTREMITY STIFFNESS RELATIVE TO ITS EFFECTS ON PERFORMANCE AND INJURY. EVIDENCE SUGGESTS THAT AN OPTIMAL AMOUNT OF LOWER EXTREMITY STIFFNESS IS REQUIRED FOR SUCCESSFUL ATHLETIC PERFORMANCE, AS TOO MUCH OR TOO LITTLE CAN BE DETRIMENTAL AND POSSIBLY INJURY INDUCING. METHODS OF MEASURING LOWER EXTREMITY STIFFNESS AND FAST STRETCH-SHORTENING CYCLE PERFORMANCE ARE SUGGESTED. IN TERMS OF TRAINING, IT IS RECOMMENDED THAT A COMBINATION OF STRENGTH AND PLYOMETRIC TRAINING BE PERFORMED, AS WELL AS CORRECT EXECUTION OF LANDING MECHANICS TO IMPROVE INTERMUSCULAR COORDINATION AND TO AVOID INJURY-PROVOKING DOMINANT AGONIST-TO-ANTAGONIST COACTIVATION RATIOS.

The effects of postactivation potentiation on golf club head speed.

Abstract Read, PJ, Miller, SC, and Turner, AN. The effects of postactivation potentiation on golf club head speed. J Strength Cond Res 27(6): 1579–1582, 2013—In golf, an increase in club head speed (CHS) has been shown to increase driving distance and is correlated with handicap. The purpose of this study was to investigate the effect of a postactivation potentiation (PAP) intervention on CHS. A FlightScope launch monitor was used to record CHS in 16 golfers (aged 20.1 ± 3.24 years, handicap 5.8 ± 2.26) during 2 testing sessions that were separated by 1 hour, using a counterbalanced design. The mean CHS of 3 swings was recorded with (experimental) and without (control) 3 preceding countermovement jumps (CMJs). An increase in CHS of 2.25 mph (effect size, 0.16; p < 0.05) 1 minute after the CMJ intervention was recorded. Therefore, acute enhancements in CHS are possible when performing a CMJ before a golf drive. This may have implications for training and on-course performance enhancement as a result of increased driving distance and possible reductions in handicap; this PAP intervention is practically viable.

Reliability of the Tuck Jump Injury Risk Screening Assessment in Elite Male Youth Soccer Players

Abstract Read, PJ, Oliver, JL, de Ste Croix, MBA, Myer, GD, and Lloyd, RS. Reliability of the tuck jump injury risk screening assessment in elite male youth soccer players. J Strength Cond Res 30(6): 1510–1516, 2016—Altered neuromuscular control has been suggested as a mechanism for injury in soccer players. Ligamentous injuries most often occur during dynamic movements, such as decelerations from jump-landing maneuvers where high-risk movement patterns are present. The assessment of kinematic variables during jump-landing tasks as part of a preparticipation screen is useful in the identification of injury risk. An example of a field-based screening tool is the repeated tuck jump assessment. The purpose of this study was to analyze the within-subject variation of the tuck jump screening assessment in elite male youth soccer players. Twenty-five pre-peak height velocity (PHV) and 25 post-PHV elite male youth soccer players from the academy of a professional English soccer club completed the assessment. A test-retest design was used to explore the within-subject intersession reliability. Technique was graded retrospectively against the 10-point criteria set out in the screening protocol using two-dimensional video cameras. The typical error range reported for tuck jump total score (0.90–1.01 in pre-PHV and post-PHV players respectively) was considered acceptable. When each criteria was analyzed individually, kappa coefficient determined that knee valgus was the only criterion to reach substantial agreement across the two test sessions for both groups. The results of this study suggest that although tuck jump total score may be reliably assessed in elite male youth soccer players, caution should be applied in solely interpreting the composite score due to the high within-subject variation in a number of the individual criteria. Knee valgus may be reliably used to screen elite youth male soccer players for this plyometric technique error and for test-retest comparison.

Injury Risk Factors in Male Youth Soccer Players

ABSTRACT YOUNG ATHLETES PARTICIPATING IN HIGH-INTENSITY SPORT DISPLAY AN INHERENT RISK OF SPORTS-RELATED INJURY, AND THIS IS HEIGHTENED AT VARIOUS STAGES OF GROWTH AND MATURATION. RECENT TRENDS HAVE HIGHLIGHTED A RANGE OF INJURY RISK FACTORS AND THE IMPORTANCE OF INJURY PREVENTION STRATEGIES WITHIN FEMALE SOCCER PLAYERS. HOWEVER, THERE IS A PAUCITY OF INFORMATION PERTAINING TO MALE YOUTH PLAYERS. THIS ARTICLE PROVIDES AN OVERVIEW OF THE AVAILABLE LITERATURE AND OUTLINES A RANGE OF RISK FACTORS THAT MAY INCREASE RELATIVE RISK OF INJURY IN MALE YOUTH SOCCER PLAYERS, INCLUDING GROWTH AND MATURATION, MOVEMENT SKILL, FATIGUE, AND PREVIOUS INJURY.

Data analysis for strength and conditioning coaches: using Excel to analyze reliability, differences, and relationships

ABSTRACT STATISTICAL ANALYSIS IS CRUCIAL TO THE ROLE OF STRENGTH AND CONDITIONING, AND COACHES SHOULD BE ABLE TO IDENTIFY WHETHER THEIR DATA ARE RELIABLE AND OBJECTIVELY DETERMINE DIFFERENCES AND RELATIONSHIPS. THESE ANALYTICAL SKILLS ARE CENTRAL TO OUR ABILITY OF UNCOVERING TRENDS AND ASSOCIATIONS, MAKING PREDICTIONS AND ASSESSING THE EFFICACY OF TRAINING PROGRAMS. THIS ARTICLE REVIEWS STATISTICAL TESTS AVAILABLE THROUGH MICROSOFT EXCEL, COVERING RELIABILITY (THROUGH THE COEFFICIENT OF VARIATION), THE SMALLEST WORTHWHILE CHANGE (I.E., THE FIRST MEANINGFUL DIFFERENCE IN SCORES), EFFECT SIZES (I.E., THE MAGNITUDE OF CHANGE BETWEEN PERFORMANCE SCORES), AND RELATIONSHIPS (I.E., CORRELATIONS).

Considerations for the Development of Agility During Childhood and Adolescence

ABSTRACT DESPITE BEING RECOGNIZED AS AN ESSENTIAL COMPONENT OF SPORTS PERFORMANCE, AGILITY DEVELOPMENT IN YOUTHS IS LARGELY UNDER-RESEARCHED. THIS ARTICLE REVIEWS THE EVIDENCE EXAMINING THE EFFECTS OF GROWTH, MATURATION AND TRAINING ON BOTH CHANGE OF DIRECTION SPEED AND COGNITIVE PROCESSING IN CHILDREN AND ADOLESCENTS, AND HOW COMBINED, THESE FACTORS MAY INFLUENCE AGILITY. TRAINING GUIDELINES ARE PROVIDED TO HELP STRENGTH AND CONDITIONING COACHES PRESCRIBE AGILITY TRAINING FOR YOUTHS AT DIFFERENT STAGES OF MATURATION, IN A SAFE AND EFFECTIVE MANNER.

Consistency of Field-Based Measures of Neuromuscular Control Using Force Plate Diagnostics in Elite Male Youth Soccer Players

Abstract Read, P, Oliver, JL, Croix, MD, Myer, GD, and Lloyd, RS. Consistency of field-based measures of neuromuscular control using force-plate diagnostics in elite male youth soccer players. J Strength Cond Res 30(12): 3304–3311, 2016—Deficits in neuromuscular control during movement patterns such as landing are suggested pathomechanics that underlie sport-related injury. A common mode of assessment is measurement of landing forces during jumping tasks; however, these measures have been used less frequently in male youth soccer players, and reliability data are sparse. The aim of this study was to examine the reliability of a field-based neuromuscular control screening battery using force-plate diagnostics in this cohort. Twenty-six pre–peak height velocity (PHV) and 25 post-PHV elite male youth soccer players completed a drop vertical jump (DVJ), single-leg 75% horizontal hop and stick (75%HOP), and single-leg countermovement jump (SLCMJ). Measures of peak landing vertical ground reaction force (pVGRF), time to stabilization, time to pVGRF, and pVGRF asymmetry were recorded. A test-retest design was used, and reliability statistics included change in mean, intraclass correlation coefficient, and coefficient of variation (CV). No significant differences in mean score were reported for any of the assessed variables between test sessions. In both groups, pVGRF and asymmetry during the 75%HOP and SLCMJ demonstrated largely acceptable reliability (CV ⩽ 10%). Greater variability was evident in DVJ pVGRF and all other assessed variables, across the 3 protocols (CV range = 13.8–49.7%). Intraclass correlation coefficient values ranged from small to large and were generally higher in the post-PHV players. The results of this study suggest that pVGRF and asymmetry can be reliably assessed using a 75%HOP and SLCMJ in this cohort. These measures could be used to support a screening battery for elite male youth soccer players and for test-retest comparison.