Adrian B. Schultz

The effects of different speed training protocols on sprint acceleration kinematics and muscle strength and power in field sport athletes.

Abstract Lockie, RG, Murphy, AJ, Schultz, AB, Knight, TJ, and Janse de Jonge, XAK. The effects of different speed training protocols on sprint acceleration kinematics and muscle strength and power in field sport athletes. J Strength Cond Res 26(6): 1539–1550, 2012—A variety of resistance training interventions are used to improve field sport acceleration (e.g., free sprinting, weights, plyometrics, resisted sprinting). The effects these protocols have on acceleration performance and components of sprint technique have not been clearly defined in the literature. This study assessed 4 common protocols (free sprint training [FST], weight training [WT], plyometric training [PT], and resisted sprint training [RST]) for changes in acceleration kinematics, power, and strength in field sport athletes. Thirty-five men were divided into 4 groups (FST: n = 9; WT: n = 8; PT: n = 9; RST: n = 9) matched for 10-m velocity. Training involved two 60-minute sessions per week for 6 weeks. After the interventions, paired-sample t-tests identified significant (p ⩽ 0.05) within-group changes. All the groups increased the 0- to 5-m and 0- to 10-m velocity by 9–10%. The WT and PT groups increased the 5- to 10-m velocity by approximately 10%. All the groups increased step length for all distance intervals. The FST group decreased 0- to 5-m flight time and step frequency in all intervals and increased 0- to 5-m and 0- to 10-m contact time. Power and strength adaptations were protocol specific. The FST group improved horizontal power as measured by a 5-bound test. The FST, PT, and RST groups all improved reactive strength index derived from a 40-cm drop jump, indicating enhanced muscle stretch-shortening capacity during rebound from impacts. The WT group increased absolute and relative strength measured by a 3-repetition maximum squat by approximately 15%. Step length was the major limiting sprint performance factor for the athletes in this study. Correctly administered, each training protocol can be effective in improving acceleration. To increase step length and improve acceleration, field sport athletes should develop specific horizontal and reactive power.

A preliminary investigation into the relationship between functional movement screen scores and athletic physical performance in female team sport athletes

There is little research investigating relationships between the Functional Movement Screen (FMS) and athletic performance in female athletes. This study analyzed the relationships between FMS (deep squat; hurdle step [HS]; in-line lunge [ILL]; shoulder mobility; active straight-leg raise [ASLR]; trunk stability push-up; rotary stability) scores, and performance tests (bilateral and unilateral sit-and-reach [flexibility]; 20-m sprint [linear speed]; 505 with turns from each leg; modified T-test with movement to left and right [change-of-direction speed]; bilateral and unilateral vertical and standing broad jumps; lateral jumps [leg power]). Nine healthy female recreational team sport athletes (age = 22.67 ± 5.12 years; height = 1.66 ± 0.05 m; body mass = 64.22 ± 4.44 kilograms) were screened in the FMS and completed the afore-mentioned tests. Percentage between-leg differences in unilateral sit-and-reach, 505 turns and the jumps, and difference between the T-test conditions, were also calculated. Spearmans correlations (p ≤ 0.05) examined relationships between the FMS and performance tests. Stepwise multiple regressions (p ≤ 0.05) were conducted for the performance tests to determine FMS predictors. Unilateral sit-and-reach positive correlated with the left-leg ASLR (r = 0.704-0.725). However, higher-scoring HS, ILL, and ASLR related to poorer 505 and T-test performance (r = 0.722-0.829). A higher-scored left-leg ASLR related to a poorer unilateral vertical and standing broad jump, which were the only significant relationships for jump performance. Predictive data tended to confirm the correlations. The results suggest limitations in using the FMS to identify movement deficiencies that could negatively impact athletic performance in female team sport athletes.

Can Selected Functional Movement Screen Assessments Be Used to Identify Movement Deficiencies That Could Affect Multidirectional Speed and Jump Performance

Abstract Lockie, RG, Schultz, AB, Jordan, CA, Callaghan, SJ, Jeffriess, MD, and Luczo, TM. Can selected functional movement screen assessments be used to identify movement deficiencies that could affect multidirectional speed and jump performance? J Strength Cond Res 29(1): 195–205, 2015—The Functional Movement Screen (FMS) includes lower-body focused tests (deep squat [DS], hurdle step, in-line lunge) that could assist in identifying movement deficiencies affecting multidirectional sprinting and jumping, which are important qualities for team sports. However, the hypothesized relationship with athletic performance lacks supportive research. This study investigated relationships between the lower-body focused screens and overall FMS performance and multidirectional speed and jumping capabilities in team sport athletes. Twenty-two healthy men were assessed in the FMS, and multidirectional speed (0- to 5-m, 0- to 10-m, 0- to 20-m sprint intervals; 505 and between-leg turn differences, modified T-test and differences between initial movement to the left or right); and bilateral and unilateral multidirectional jumping (vertical [VJ], standing long [SLJ], and lateral jump) tests. Pearsons correlations (r) were used to calculate relationships between screening scores and performance tests (p ⩽ 0.05). After the determination of any screens relating to athletic performance, subjects were stratified into groups (3 = high-performing group; 2 = intermediate-performing group; 1 = low-performing group) to investigate movement compensations. A 1-way analysis of variance (p ⩽ 0.05) determined any between-group differences. There were few significant correlations. The DS did moderately correlate with between-leg 505 difference (r = −0.423), and bilateral VJ (r = −0.428) and SLJ (r = −0.457). When stratified into groups according to DS score, high performers had a 13% greater SLJ when compared with intermediate performers, which was the only significant result. The FMS seems to have minimal capabilities for identifying movement deficiencies that could affect multidirectional speed and jumping in male team sport athletes.

Influence of Sprint Acceleration Stance Kinetics on Velocity and Step Kinematics in Field Sport Athletes

Abstract Lockie, RG, Murphy, AJ, Schultz, AB, Jeffriess, MD, and Callaghan, SJ. Influence of sprint acceleration stance kinetics on velocity and step kinematics in field sport athletes. J Strength Cond Res 27(9): 2494–2503, 2013—The interaction between step kinematics and stance kinetics determines sprint velocity. However, the influence that stance kinetics has on effective acceleration in field sport athletes requires clarification. About 25 men (age = 22.4 ± 3.2 years; mass = 82.8 ± 7.2 kg; height = 1.81 ± 0.07 m) completed twelve 10-m sprints, 6 sprints each for kinematic and kinetic assessment. Pearsons correlations (p ⩽ 0.05) examined relationships between 0–5, 5–10, and 0–10 m velocity; step kinematics (mean step length [SL], step frequency, contact time [CT], flight time over each interval); and stance kinetics (relative vertical, horizontal, and resultant force and impulse; resultant force angle; ratio of horizontal to resultant force [RatF] for the first, second, and last contacts within the 10-m sprint). Relationships were found between 0–5, 5–10, and 0–10 m SL and 0–5 and 0–10 m velocity (r = 0.397–0.535). CT of 0–5 and 0–10 m correlated with 5–10 m velocity (r = −0.506 and −0.477, respectively). Last contact vertical force correlated with 5–10 m velocity (r = 0.405). Relationships were established between the second and last contact vertical and resultant force and CT over all intervals (r = −0.398 to 0.569). First and second contact vertical impulse correlated with 0–5 m SL (r = 0.434 and 0.442, respectively). Subjects produced resultant force angles and RatF suitable for horizontal force production. Faster acceleration in field sport athletes involved longer steps, with shorter CT. Greater vertical force production was linked with shorter CT, illustrating efficient force production. Greater SLs during acceleration were facilitated by higher vertical impulse and appropriate horizontal force. Speed training for field sport athletes should be tailored to encourage these technique adaptations.

The relationship between bilateral differences of knee flexor and extensor isokinetic strength and multi-directional speed

This study analyzed relationships between bilateral concentric (60 ◦ /s, 180 ◦ /s, 240 ◦ /s) and eccentric (30 ◦ /s) knee extensor and flexor strength differences, and linear (40-meter sprint), and change-of-direction (T-test) speed in 16 male team sport athletes. It was hypothesized that lower between-leg strength differences would be associated with faster speeds. Subjects were divided into faster and slower groups based on total time; a one-way analysis of variance (p 0.05) determined bilateral torque and work differences that distinguished the groups. All data was combined to correlate (p 0.05) torque and work differences with sprint times. The faster group exhibited greater differences in concentric knee extensor torque at 240 ◦ /s (faster = 11.74 ± 8.65%; slower = 4.13 ± 4.34%), and smaller differences in eccentric knee flexor torque (faster = 5.64 ± 4.10%; slower = 12.41 ± 7.55%) and work (faster = 6.36 ± 6.65%; slower = 15.55 ± 6.05%). Negative correlations were found between concentric 180 ◦ /s and 240 ◦ /s knee extensor torque differences and sprint times; however, speed was not negatively affected. Positive correlations existed between eccentric knee flexor work differences and sprint times. Eccentric strength differences negatively impacted multi-directional speed, as balanced eccentric strength is necessary for effective sprinting, deceleration, and changing direction.

The effects of isokinetic knee extensor and flexor strength on dynamic stability as measured by functional reaching

BACKGROUND: Team sport athletes require dynamic stability in unilateral activities for their sports, which necessitates some degree of knee flexion and extension strength. OBJECTIVE: To analyze the possible association of knee extension and flexion strength with dynamic stability, as measured by the Star Excursion Balance Test (SEBT). METHODS: Sixteen male team sport athletes completed the SEBT, which involves a series of unilateral squats with the subject maximally reaching with the other leg in eight directions. Knee muscle strength was measured isokinetically both concentrically (60 ◦ /s, 180 ◦ /s, 240 ◦ /s) and eccentrically (30 ◦ /s). Subjects were divided into better and lesser groups based on mean functional reach distance. A 1-way analysis of variance (p 0.05) determined between-group differences in reach distances and relative torque. RESULTS: Subjects with better dynamic stability generated greater knee extensor torque concentrically at 180 ◦ /s for the right leg, and at all speeds for the left leg. The effects of knee strength were particularly noteworthy for the left leg, as subjects with better dynamic stability reached significantly further across all 8 directions. CONCLUSION: The results indicate that greater knee extensor strength may enhance unilateral dynamic stability in team sport athletes.

Planned and reactive agility performance in semiprofessional and amateur basketball players

CONTEXT Research indicates that planned and reactive agility are different athletic skills. These skills have not been adequately assessed in male basketball players. PURPOSE To define whether 10-m-sprint performance and planned and reactive agility measured by the Y-shaped agility test can discriminate between semiprofessional and amateur basketball players. METHODS Ten semiprofessional and 10 amateur basketball players completed 10-m sprints and planned- and reactive-agility tests. The Y-shaped agility test involved subjects sprinting 5 m through a trigger timing gate, followed by a 45° cut and 5-m sprint to the left or right through a target gate. In the planned condition, subjects knew the cut direction. For reactive trials, subjects visually scanned to find the illuminated gate. A 1-way analysis of variance (P < .05) determined between-groups differences. Data were pooled (N = 20) for a correlation analysis (P < .05). RESULTS The reactive tests differentiated between the groups; semiprofessional players were 6% faster for the reactive left (P = .036) and right (P = .029) cuts. The strongest correlations were between the 10-m sprints and planned-agility tests (r = .590-.860). The reactive left cut did not correlate with the planned tests. The reactive right cut moderately correlated with the 10-m sprint and planned right cut (r = .487-.485). CONCLUSIONS The results reemphasized that planned and reactive agility are separate physical qualities. Reactive agility discriminated between the semiprofessional and amateur basketball players; planned agility did not. To distinguish between male basketball players of different ability levels, agility tests should include a perceptual and decision-making component.

The effects of traditional and enforced stopping speed and agility training on multidirectional speed and athletic function.

Abstract Lockie, RG, Schultz, AB, Callaghan, SJ, and Jeffriess, MD. The effects of traditional and enforced stopping speed and agility training on multidirectional speed and athletic function. J Strength Cond Res 28(6): 1538–1551, 2014—This study investigated the effects of a traditional speed and agility training program (TSA) and an enforced stopping program emphasizing deceleration (ESSA). Twenty college-aged team sport athletes (16 males, 4 females) were allocated into the training groups. Pretesting and posttesting included: 0–10, 0–20, 0–40 m sprint intervals, change-of-direction, and acceleration test (CODAT), T-test (multidirectional speed); vertical, standing broad, lateral, and drop jumps, medicine ball throw (power); Star Excursion Balance Test (posteromedial, medial, anteromedial reaches; dynamic stability); and concentric (240°·s-1) and eccentric (30°·s−1) knee extensor and flexor isokinetic testing (unilateral strength). Both groups completed a 6-week speed and agility program. The ESSA subjects decelerated to a stop within a specified distance in each drill. A repeated measures analysis of variance determined significant (p ⩽ 0.05) within- and between-group changes. Effect sizes (Cohens d) were calculated. The TSA group improved all speed tests (d = 0.29–0.96), and most power tests (d = 0.57–1.10). The ESSA group improved the 40-m sprint, CODAT, T-test, and most power tests (d = 0.46–1.31) but did not significantly decrease 0–10 and 0–20 m times. The TSA group increased posteromedial and medial excursions (d = 0.97–1.89); the ESSA group increased medial excursions (d = 0.99–1.09). The ESSA group increased concentric knee extensor and flexor strength, but also increased between-leg knee flexor strength differences (d = 0.50–1.39). The loading associated with stopping can increase unilateral strength. Coaches should ensure deceleration drills allow for appropriate sprint distances before stopping, and athletes do not favor 1 leg for stopping after deceleration.

The Relationship between Dynamic Stability and Multidirectional Speed.

Abstract Lockie, RG, Schultz, AB, Callaghan, SJ, and Jeffriess, MD. The relationship between dynamic stability and multidirectional speed. J Strength Cond Res 30(11): 3033–3043, 2016—Dynamic stability is said to contribute to multidirectional (linear and change-of-direction) speed, although little research confirms this. This study analyzed the relationship between dynamic stability as measured by lower-limb functional reaching in 6 directions (anterolateral, lateral, posterolateral, posteromedial, medial, and anteromedial) within a modified star excursion balance test and multidirectional speed (40-m sprint: 0–10, 0–20, and 0–40 m intervals; T-test; change-of-direction and acceleration test [CODAT]). Sixteen male field sport athletes (age, 23.31 ± 5.34 years; height, 1.78 ± 0.07 m; mass, 80.60 ± 9.89 kg) completed testing. A 1-way analysis of variance determined significant (p ⩽ 0.05) differences in excursions between faster and slower subjects. All data were pooled for a Spearmans correlation analysis (p ⩽ 0.05). Faster subjects had greater left leg medial reach (76.24 ± 5.33 vs. 65.94 ± 10.75%), right leg posteromedial reach (85.20 ± 8.07 vs. 73.59 ± 12.64%), and a smaller between-leg difference in lateral reach (2.26 ± 1.85 vs. 6.46 ± 4.29%). Longer reach distances (greater dynamic stability) correlated with faster speed test times (&rgr; = −0.499 to 0.664). Dynamic stability relationships were pronounced for the change-of-direction speed tests. For example, smaller between-leg excursion differences in anterolateral, lateral, posterolateral, and posteromedial reaches related to faster T-test and CODAT times (&rgr; = 0.502–0.804). There is a relationship between dynamic stability as measured by functional reaching and multidirectional speed in field sport athletes, possibly because of similarities in movement demands and muscle recruitment. Dynamic stability training could strengthen muscles for multidirectional sprinting and develop functional joint motion.

Certain Actions from the Functional Movement Screen Do Not Provide an Indication of Dynamic Stability

Abstract Dynamic stability is an essential physical component for team sport athletes. Certain Functional Movement Screen (FMS) exercises (deep squat; left- and right-leg hurdle step; left- and right-leg in-line lunge [ILL]; left- and right-leg active straight-leg raise; and trunk stability push-up [TSPU]) have been suggested as providing an indication of dynamic stability. No research has investigated relationships between these screens and an established test of dynamic stability such as the modified Star Excursion Balance Test (mSEBT), which measures lower-limb reach distance in posteromedial, medial, and anteromedial directions, in team sport athletes. Forty-one male and female team sport athletes completed the screens and the mSEBT. Participants were split into high-, intermediate-, and low-performing groups according to the mean of the excursions when both the left and right legs were used for the mSEBT stance. Any between-group differences in the screens and mSEBT were determined via a one-way analysis of variance with Bonferroni post hoc adjustment (p < 0.05). Data was pooled for a correlation analysis (p < 0.05). There were no between-group differences in any of the screens, and only two positive correlations between the screens and the mSEBT (TSPU and right stance leg posteromedial excursion, r = 0.37; left-leg ILL and left stance leg posteromedial excursion, r = 0.46). The mSEBT clearly indicated participants with different dynamic stability capabilities. In contrast to the mSEBT, the selected FMS exercises investigated in this study have a limited capacity to identify dynamic stability in team sport athletes.