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1.
PLoS One ; 19(6): e0302647, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38857238

RESUMEN

The primary aim of this study was to present the physical profile of female cricketers. Secondary, was to assess any differences between playing standard (professional vs. non-professional) and position (seam bowler vs. non-seam bowler). Fifty-four female cricketers (professional seam bowler [n = 16]; professional non-seam bowler [n = 17]; non-professional seam bowler [n = 10]; non-professional non-seam bowler [n = 11]) undertook a battery of physical and anthropometric assessments during the off-season period. Participant's physical profile was assessed via the broad jump, countermovement jump, isometric mid-thigh pull (IMTP), 20 m sprint, run-2 cricket specific speed test, and Yo-Yo Intermittent Recovery Test Level-1 (Yo-Yo-IR1). The sum-of-eight skinfold measurement was also recorded for professional cricketers only. Differences between playing standard and position were assessed with a two-way ANOVA. Seam bowlers possessed a significantly (p < 0.04) greater stature and had a higher body mass than non-seam bowlers. Non-seam bowlers recorded significantly (p < 0.01) further broad jump, higher normalised peak vertical force during the IMTP, and ran greater distances during the Yo-Yo-IR1. Professional cricketers produced significantly further run distances for the Yo-Yo-IR1 and faster run-2 times for the dominant turning side than non-professional cricketers. This study provides valuable insights into the physical profile of female cricketers across playing standards and positions which practitioners can use to direct and enhance training outcomes.


Asunto(s)
Rendimiento Atlético , Críquet , Humanos , Femenino , Críquet/fisiología , Rendimiento Atlético/fisiología , Adulto , Adulto Joven , Carrera/fisiología , Atletas
2.
Sports Biomech ; : 1-17, 2021 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-34255613

RESUMEN

The effects of an eight-week off-season strength training program upon lower-body strength, power, eccentric capacity, front foot contact (FFC) kinetics, and ball release speed (BRS) in pace bowlers were investigated. Ten elite-academy pace bowlers completed the intervention, and pre- and post-testing. Pre- and post-testing included: double (DLDL) and single leg (SLDL) drop landings; isometric mid-thigh pull (IMTP); countermovement jump; and pace bowling performance (two-over bowling spell measuring BRS and FFC kinetics). Changes from pre- to post-testing were assessed with paired sample t tests (p≤ 0.01), effects sizes and statistical parametrical mapping. Post-testing revealed a significant decrease in peak normalised vertical force during DLDL and SLDL with large effects and a significant, moderate effect increase in IMTP. There was no significant changes in BRS. Concomitantly, neither discrete scalar (p= 0.15-0.58) nor vector field analysis kinetics during FFC indicated significant changes. No significant alterations in FFC kinetics may explain the lack of improvement in BRS (pre = 31.55 ± 1.44 m/s; post = 31.79 ± 1.33 m/s). This study indicated an eight-week strength training program can improve strength and eccentric capacity in pace bowlers, and these changes when developed in the absence of skills training neither improved nor decreased pace bowling performance.

3.
Sports (Basel) ; 8(12)2020 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-33255275

RESUMEN

This study investigated whether the barbell hip thrust (BHT) enhanced change-of-direction (COD) speed measured by the 505 COD speed test. Forty recreationally trained individuals completed three sessions. Session 1 included one-repetition maximum (1RM) BHT testing to measure absolute and relative strength. Sessions 2 and 3 involved two counter-balanced conditioning activities (CAs): 3 sets × 5 repetitions of the BHT at 85% 1RM and a control condition (CC; 6 min rest). The 505 COD speed test was performed 5 and 2.5 min pre-CA, and 4, 8, 12, and 16 min post-CA in each session. A 2 × 5 repeated-measures ANOVA (p < 0.05) calculated performance changes across time post-CA. A 2 × 2 repeated-measures ANOVA analyzed best potentiated performance. Partial correlations controlling for sex calculated relationships between the 1RM BHT and 505 COD speed test percent potentiation. There was a significant main effect for time (p < 0.001), but not for condition (p = 0.271) or condition × time (p = 0.295). There were no significant correlations between 1RM BHT and potentiation. The 85% 1RM BHT did potentiate the 505 4-16 min post-CA but no more than the CC. Nonetheless, a heavy BHT could be programmed prior to COD drills as COD speed could be potentiated and performance improved in men and women.

4.
Biol Sport ; 37(4): 423-428, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33343076

RESUMEN

Volleyball players need to sprint and change direction during a match. Lower-body power, often measured by jump tests, could contribute to faster movements. How different jumps relate to linear and change-of-direction (COD) speed has not been analyzed in Division I (DI) collegiate women's volleyball players. Fifteen female volleyball players completed the vertical jump (VJ), two-step approach jump (AppJ), and standing broad jump (SBJ). Peak power and power-to-body mass ratio (P:BM) were derived from VJ and AppJ height; relative SBJ was derived from SBJ distance. Linear speed was measured via a 20-m sprint (0-10 and 0-20 m intervals); COD speed was measured using the pro-agility shuttle. Pearson's correlations (p < 0.05) calculated relationships between the power variables, and speed tests. There were no significant relationships between the power variables and the 0-10 m sprint interval. Greater VJ height (r = -0.534) and P:BM (r = -0.557) related to a faster 0-20 m sprint interval. This be due to a greater emphasis on the stretch-shortening cycle to generate speed over 20 m. However, although a 20-m sprint may provide a measure of general athleticism, the distance may not be specific to volleyball. This was also indicated as the AppJ did not relate to any of the speed tests. Nonetheless, VJ height and P:BM, and SBJ distance and relative SBJ, all negatively correlated with the proagility shuttle (r = -0.548 to -0.729). DI women's collegiate volleyball players could develop absolute and relative power in the vertical and horizontal planes to enhance COD speed.

5.
Int J Sports Physiol Perform ; 15(10): 1485-1489, 2020 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-32994385

RESUMEN

PURPOSE: To investigate whether changes in delivery length (ie, short, good, and full) lead to alterations in whole-body biomechanical loading as determined by ground reaction force during front-foot contact of the delivery stride for pace bowlers. Current load-monitoring practices of pace bowling in cricket assume equivocal biomechanical loading as only the total number of deliveries are monitored irrespective of delivery length. METHODS: A total of 16 male pace bowlers completed a 2-over spell at maximum intensity while targeting different delivery lengths (short, 7-10 m; good, 4-7 m; and full, 0-4 m from the batter's stumps). In-ground force plates were used to determine discrete (vertical and braking force, impulse, and loading rates) and continuous front-foot contact ground reaction force. Repeated-measures analysis of variance (P < .05), effects size, and statistical parametrical mapping were used to determine differences between delivery lengths. RESULTS: There were no significant differences between short, good, and full delivery lengths for the discrete and continuous kinetic variables investigated (P = .19-1.00), with trivial to small effect sizes. CONCLUSION: There were minimal differences in front-foot contact biomechanics for deliveries of different lengths (ie, short, good, and full). These data reinforce current pace bowling load-monitoring practices (ie, counting the number of deliveries), as changes in delivery length do not affect the whole-body biomechanical loading experienced by pace bowlers. This is of practical importance as it retains simplicity in load-monitoring practice that is used widely across different competition levels and ages.


Asunto(s)
Fenómenos Biomecánicos , Críquet/fisiología , Pie , Humanos , Cinética , Masculino
6.
Sports (Basel) ; 8(5)2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32455857

RESUMEN

Forty recreationally-trained individuals completed four testing sessions to determine whether lateral bounds (LB) or weighted lateral bounds enhanced change-of-direction (COD) speed measured by the 505 COD speed test. Session 1 included vertical jump and lateral bound (LB) testing to measure power. Sessions 2-4 involved three randomized conditioning activities (CA): 3 × 5 LB; 3 × 5 weighted LB (10% body mass provided by a weighted vest); and a control condition (4-min rest). The 505 COD speed test was performed 5- and 2.5-min pre-CA, and ~15 s, 4, 8, 12, and 16 min post-CA. A 3 × 6 repeated measures analysis of variance (ANOVA) calculated performance changes across time points post-CA. A 3 × 2 repeated measures ANOVA analyzed best potentiated performance. Smallest worthwhile change (SWC) measured within-subject 505 COD speed test performance. Partial correlations controlling for sex calculated relationships between the vertical jump, LB, and percent potentiation. There were no differences (p = 0.919) in 505 time relative to baseline for any CA, nor was the SWC exceeded. The best potentiated 505 time was faster (p < 0.001) than baseline for all CA, with no between-CA differences. There were no significant (p = 0.056-0.993) correlations between power and potentiation. LB and weighted LB did not potentiate the 505 COD speed test, although performance was not hindered.

7.
Sports Biomech ; 19(3): 307-321, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29767577

RESUMEN

This study assessed the reliability and validity of segment measured accelerations in comparison to front foot contact (FFC) ground reaction force (GRF) during the delivery stride for cricket pace bowlers. Eleven recreational bowlers completed a 30-delivery bowling spell. Trunk- and tibia-mounted inertial measurement units (IMUs) were used to measure accelerations, converted to force, for comparisons to force plate GRF discrete measures. These measures included peak force, impulse and the continuous force-time curve in the vertical and braking (horizontal) planes. Reliability and validity was determined by intra-class correlation coefficients (ICC), coefficient of variation (CV), Bland-Altman plots, paired sample t-tests, Pearson's correlation and one-dimensional (1D) statistical parametrical mapping (SPM). All ICC (0.90-0.98) and CV (4.23-7.41%) were acceptable, except for tibia-mounted IMU braking peak force (CV = 12.44%) and impulse (CV = 18.17%) and trunk vertical impulse (CV = 17.93%). Bland-Altman plots revealed wide limits of agreement between discrete IMU force signatures and force plate GRF. The 1D SPM outlined numerous significant (p < 0.01) differences between trunk- and tibia-located IMU-derived measures and force plate GRF traces in vertical and braking (horizontal) planes. The trunk- and tibia-mounted IMUs appeared to not represent the GRF experienced during pace bowling FFC when compared to a gold-standard force plate.


Asunto(s)
Acelerometría/métodos , Críquet/fisiología , Acelerometría/instrumentación , Fenómenos Biomecánicos , Estudios Transversales , Pie/fisiología , Humanos , Pierna/fisiología , Reproducibilidad de los Resultados , Análisis y Desempeño de Tareas , Torso/fisiología , Dispositivos Electrónicos Vestibles
8.
Sports (Basel) ; 7(9)2019 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-31480269

RESUMEN

Pace bowlers must often perform extended bowling spells with maximal ball release speed (BRS) while targeting different delivery lengths when playing a multi-day match. This study investigated the effect of an eight over spell upon pace bowling biomechanics and performance at different delivery lengths. Nine male bowlers (age = 18.8 ± 1.7 years) completed an eight over spell, while targeting different lengths (short: 7-10 m, good: 4-7 m, full: 0-4 m from the batter's stumps, respectively) in a randomized order. Trunk, knee and shoulder kinematics and ground reaction forces at front foot contact (FFC), as well as run-up velocity and BRS were measured. Paired sample t-tests (p ≤ 0.01), Hedges' g effect sizes, and statistical parametrical mapping were used to assess differences between mean variables from the first and last three overs. No significant differences (p = 0.05-0.98) were found in any discrete or continuous variables, with the magnitude of difference being trivial-to-medium (g = 0.00-0.73) across all variables. Results suggest pace bowlers sustain BRS through a single eight over spell while tolerating the repeatedly high whole-body biomechanical loads as suggested by maintaining the kinematics or technique at the assessed joints during FFC. Practically, the findings are advantageous for bowling performance and support current bowling load monitoring practices.

9.
Sports (Basel) ; 6(3)2018 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-30223573

RESUMEN

The close-grip bench press (CGBP) is a variation of the traditional bench press (TBP) that uses a narrower grip (~95% biacromial distance) and has application for athletes performing explosive arm actions where the hands are positioned close to the torso. Limited research has investigated CGBP peak power. Twenty-six strength-trained individuals completed a one-repetition maximum TBP and CGBP. During two other sessions, subjects completed two repetitions as explosively as possible with loads from 20% to 90% for each exercise, with peak power measured by a linear position transducer. A factorial ANOVA calculated between- and within-exercise differences in peak power. Partial correlations controlling for sex determined relationships between absolute and relative strength and peak power load. Peak power for the TBP occurred at 50% 1RM, and 30% 1RM for the CGBP. There were no significant (p = 0.680) differences between peak power at each load when comparing the TBP and CGBP. For the within-exercise analysis, there were generally no significant differences in TBP and CGBP peak power for the 20⁻50% 1RM loads. There were no significant relationships between strength and peak power load (p = 0.100⁻0.587). A peak power loading range of 20⁻50% 1RM for the TBP and CGBP is suggested for strength-trained individuals.

10.
J Strength Cond Res ; 32(11): 3011-3019, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29045317

RESUMEN

Lockie, RG, Moreno, MR, Orjalo, AJ, Lazar, A, Liu, TM, Stage, AA, Birmingham-Babauta, SA, Stokes, JJ, Giuliano, DV, Risso, FG, Davis, DL, and Callaghan, SJ. Relationships between height, arm length, and leg length on the mechanics of the conventional and high-handle hexagonal bar deadlift. J Strength Cond Res 32(11): 3011-3019, 2018-The study investigated relationships between arm length (AL) and leg length (LL) and conventional deadlift (CD) and high-handle hexagonal bar deadlift (HHBD) mechanics. Twenty-three resistance-trained subjects (14 men and 9 women) completed a 1 repetition maximum CD and HHBD. A linear position transducer was used to measure lift distance and duration; peak and mean power, velocity, and force; time to peak power and velocity; and work. Right AL and LL were measured, and AL-to-LL ratio (AL:LL) was also calculated. Spearman's correlations (ρ; p ≤ 0.05) computed relationships between anthropometry and deadlift mechanics separately for men and women. For the HHBD, greater height and LL related to greater lift distance and work (ρ = 0.54-0.68); a higher AL:LL related to time to peak power and velocity occurring sooner (ρ = -0.67 to 0.78). For the HHBD, greater height and LL related to greater lift distance and work; a higher AL:LL related to time to peak power and velocity occurring sooner in the lift (ρ = 0.54-0.77). In women, greater height, AL, and LL related to a longer CD lift distance (ρ = 0.67-0.92). For the HHBD, greater height, AL, and LL related to a longer lift distance and greater mean velocity (ρ = 0.69-0.96). There was a negative relationship between AL and lift time (ρ = -0.83), which meant longer arms resulted in a lower HHBD lift time. Arm length may have influenced women more because of the fixed dimensions of the hexagonal bar. Coaches should be cognizant of potential differences in CD and HHBD work when performed by individuals of different body sizes.


Asunto(s)
Brazo/anatomía & histología , Estatura , Pierna/anatomía & histología , Levantamiento de Peso/fisiología , Estudios Transversales , Femenino , Humanos , Masculino , Fuerza Muscular , Adulto Joven
11.
J Strength Cond Res ; 32(1): 150-161, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28394830

RESUMEN

Lockie, RG, Moreno, MR, Lazar, A, Risso, FG, Liu, TM, Stage, AA, Birmingham-Babauta, SA, Torne, IA, Stokes, JJ, Giuliano, DV, Davis, DL, Orjalo, AJ, and Callaghan, SJ. The 1 repetition maximum mechanics of a high-handle hexagonal bar deadlift compared with a conventional deadlift as measured by a linear position transducer. J Strength Cond Res 32(1): 150-161, 2018-The high-handle hexagonal bar deadlift (HHBD), a variation of the conventional deadlift (CD), is said to reduce the lift range of motion, which may change the mechanics of the lift. However, no research has investigated this. This study compared the mechanics between a 1 repetition maximum (1RM) CD and HHBD. Thirty-one strength-trained subjects (21 men, 10 women) completed a 1RM CD and HHBD. A linear position transducer measured lift distance, duration, and work; and peak and mean power, velocity, and force. The presence of a sticking region (SR) was determined for each lift. A repeated-measures analysis of variance (ANOVA) calculated differences between 1RM CD and HHBD mechanics. A one-way ANOVA compared the mechanics of each lift between subjects who exhibited an SR or not, and the SR between the CD and HHBD. Significance was set at p < 0.01. Subjects lifted a greater load in the HHBD (154.50 ± 45.29 kg) compared with the CD (134.72 ± 40.63 kg). Lift distance and duration were 22 and 25% shorter during the 1RM HHBD, respectively. The HHBD featured greater peak power and velocity, and peak and mean force; more work was done in the CD. Most subjects did not exhibit a CD (68%) or HHBD (77%) SR. There were no differences in CD or HHBD mechanics between subjects with or without an SR, and no differences in SR region distance or duration between the CD and HHBD. Greater force can be generated in the HHBD, which could have implications for strength-training adaptations over time.


Asunto(s)
Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Levantamiento de Peso/fisiología , Adulto , Fenómenos Biomecánicos , Estudios Cruzados , Femenino , Humanos , Masculino , Rango del Movimiento Articular , Adulto Joven
12.
Sports (Basel) ; 5(3)2017 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-29910406

RESUMEN

The close-grip bench press (CGBP) is a variation of the traditional bench press (TBP) that uses a narrower grip (~95% of biacromial distance (BAD)) and has potential application for athletes performing explosive arm actions from positions where the hands are held close to the torso. Limited research has investigated CGBP mechanics compared to the TBP. Twenty-seven resistance-trained individuals completed a one-repetition maximum TBP and CGBP. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% BAD. A linear position transducer measured lift distance and duration; peak and mean power, velocity, and force; distance and time when peak power occurred; and work. Pre-sticking region (PrSR), sticking region, and post-sticking region distance and duration for each lift was measured. A repeated measures ANOVA was used to derive differences between TBP and CGBP mechanics (p < 0.01); effect sizes (d) were also calculated. A greater load was lifted in the TBP, thus mean force was greater (d = 0.16⁻0.17). Peak power and velocity were higher in the CGBP, which had a longer PrSR distance (d = 0.49⁻1.32). The CGBP could emphasize power for athletes that initiate explosive upper-body actions with the hands positioned close to the torso.

13.
J Hum Kinet ; 60: 19-28, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29339982

RESUMEN

The study aim was to determine relationships between mechanical variables in the one-repetition maximum (1RM) traditional bench press (TBP) and close-grip bench press (CGBP). Twenty resistance-trained men completed a TBP and CGBP 1RM. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% biacromial distance. A linear position transducer measured: lift distance and duration; work; and peak and mean power, velocity, and force. Paired samples t-tests (p < 0.05) compared the 1RM and mechanical variables for the TBP and CGBP; effect sizes (d) were also calculated. Pearson's correlations (r; p < 0.05) computed relationships between the TBP and CGBP. 1RM, lift duration, and mean force were greater in the TBP (d = 0.30-3.20). Peak power and velocity was greater for the CGBP (d = 0.50-1.29). The 1RM TBP correlated with CGBP 1RM, power, and force (r = 0.685-0.982). TBP work correlated with CGBP 1RM, lift distance, power, force, and work (r = 0.542-0.931). TBP power correlated with CGBP 1RM, power, force, velocity, and work (r = 0.484-0.704). TBP peak and mean force related to CGBP 1RM, power, and force (r = 0.596-0.980). Due to relationships between the load, work, power, and force for the TBP and CGBP, the CGBP could provide similar strength adaptations to the TBP with long-term use. The velocity profile for the CGBP was different to that of the TBP. The CGBP could be used specifically to improve high-velocity, upper-body pushing movements.

14.
J Strength Cond Res ; 30(11): 3024-3032, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26982972

RESUMEN

Nimphius, S, Callaghan, SJ, Spiteri, T, and Lockie, RG. Change of direction deficit: A more isolated measure of change of direction performance than total 505 time. J Strength Cond Res 30 (11): 3024-3032, 2016-Most change of direction (COD) tests use total time to evaluate COD performance. This makes it difficult to identify COD ability because the majority of time is a function of linear running. The COD deficit has been proposed as a practical measure to isolate COD ability independent of sprint speed. This study evaluated relationships between sprint time, 505 time, and COD deficit, and whether the COD deficit identified a different and more isolated measure of COD ability compared with 505 time. Seventeen cricketers performed the 505 for both left and right sides and 30-m sprint tests (with 10-m split time). The COD deficit for both sides was calculated as the difference between average 505 and 10-m time. Correlations were calculated between all variables (p ≤ 0.05). To compare 505 time and COD deficit, z-scores were calculated; the difference in these scores was evaluated for each subject. The COD deficit correlated to 505 (r = 0.74-0.81) but not sprint time (r = -0.11 to 0.10). In contrast, 505 time did correlate with sprint time (r = 0.52-0.70). Five of 17 subjects were classified differently for COD ability when comparing standardized scores for 505 time vs. COD deficit. Most subjects (88-94%) had a meaningful difference between 505 time and COD deficit. Using 505 time to determine COD ability may result in a large amount of replication to linear speed assessments. The COD deficit may be a practical tool to better isolate and identify an athlete's ability to change direction.


Asunto(s)
Rendimiento Atlético/fisiología , Carrera/fisiología , Aceleración , Adulto , Atletas , Estudios Transversales , Humanos , Masculino
15.
J Strength Cond Res ; 30(11): 3033-3043, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23942170

RESUMEN

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 Spearman's 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 (ρ = -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 (ρ = 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.


Asunto(s)
Aceleración , Extremidad Inferior/fisiología , Equilibrio Postural/fisiología , Carrera/fisiología , Adulto , Atletas , Estudios Transversales , Prueba de Esfuerzo , Humanos , Masculino , Adulto Joven
16.
J Sports Sci Med ; 14(4): 864-76, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26664285

RESUMEN

This study investigated the effects of preventative ankle taping on planned change-of-direction and reactive agility performance and peak ankle muscle activity in basketballers. Twenty male basketballers (age = 22.30 ± 3.97 years; height = 1.84 ± 0.09 meters; body mass = 85.96 ± 11.88 kilograms) with no ankle pathologies attended two testing sessions. Within each session, subjects completed six planned and six reactive randomized trials (three to the left and three to the right for each condition) of the Y-shaped agility test, which was recorded by timing lights. In one session, subjects had both ankles un-taped. In the other, both ankles were taped using a modified subtalar sling. Peak tibialis anterior, peroneus longus (PL), peroneus brevis (PB), and soleus muscle activity was recorded for both the inside and outside legs across stance phase during the directional change, which was normalized against 10-meter sprint muscle activity (nEMG). Both the inside and outside cut legs during the change-of-direction step were investigated. Repeated measures ANOVA determined performance time and nEMG differences between un-taped and taped conditions. There were no differences in planned change-of-direction or reactive agility times between the conditions. Inside cut leg PL nEMG decreased when taped for the planned left, reactive left, and reactive right cuts (p = 0.01). Outside leg PB and soleus nEMG increased during the taped planned left cut (p = 0.02). There were no other nEMG changes during the cuts with taping. Taping did not affect change-of-direction or agility performance. Inside leg PL activity was decreased, possibly due to the tape following the line of muscle action. This may reduce the kinetic demand for the PL during cuts. In conclusion, ankle taping did not significantly affect planned change-of-direction or reactive agility performance, and did not demonstrate large changes in activity of the muscle complex in healthy basketballers. Key pointsAnkle taping using the modified subtalar sling will not affect planned change-of-direction or reactive agility performance as measured by the Y-shaped agility test in healthy male basketball players.Ankle taping using the modified subtalar sling will also generally not affect the activity of the muscles about the ankle. There was some indication for reductions in the activity of the PL in the inside leg of certain cuts.The tape used for the modified subtalar sling may have supported the line of action of the PL, which could reduce the kinetic demand placed on this muscle, and provide a potential fatigue-reducing component for cutting actions.The subtalar sling taping of the ankle in healthy basketball players did not have any adverse effects on the muscle activity of the ankle-foot complex during planned change-of-direction or reactive agility performance tasks.

17.
J Hum Kinet ; 47: 19-29, 2015 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-26557187

RESUMEN

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.

18.
J Strength Cond Res ; 29(9): 2623-34, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26313578

RESUMEN

The introduction of the shorter match formats for cricket (i.e., Twenty20) requires batsmen to be proficient in sprint acceleration to increase run scoring potential. Therefore, the study aim was to identify the kinematics of faster acceleration performance of nonstriking batsmen when completing a quick single. Eighteen experienced male cricketers currently playing cricket in a regional competition in Australia completed 17.68-m sprints using a match-specific start (walking start, bat dragged through crease, leg guards worn). Timing gates recorded the 0-5 and 0-17.68 m time. Joint and step kinematics were analyzed through the first and second steps through 3-dimensional motion analysis. Subjects were split into faster and slower groups according to 0- to 5-m time, and a 1-way analysis of variance determined significant (p ≤ 0.05) between-group differences. Effect sizes and Pearson's correlations (r) were also calculated. The faster group was significantly quicker for the 0-5 and 0-17.68 m intervals and had a 10% longer first, and 11% longer second, step. Second step swing leg hip adduction was 23% greater in the faster group. A significant negative correlation (r = -0.647) was found between second step drive leg extension and 0- to 5-m time. Batsmen should cover the initial 5 m of a quick single in the shortest time possible to increase the likelihood of a successful run. This is aided by longer first and second steps and increased hip adduction to transition into normal sprint technique. Step length development should be a key consideration for coaches attempting to improve quick single performance.


Asunto(s)
Aceleración , Deportes/fisiología , Adulto , Fenómenos Biomecánicos/fisiología , Humanos , Masculino , Carrera/fisiología , Caminata/fisiología , Adulto Joven
19.
J Hum Kinet ; 49: 65-74, 2015 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-26839607

RESUMEN

This study investigated relationships between 10 m sprint acceleration, step kinematics (step length and frequency, contact and flight time), and leg muscle performance (power, stiffness, strength). Twenty-eight field sport athletes completed 10 m sprints that were timed and filmed. Velocity and step kinematics were measured for the 0-5, 5-10, and 0-10 m intervals to assess acceleration. Leg power was measured via countermovement jumps (CMJ), a five-bound test (5BT), and the reactive strength index (RSI) defined by 40 cm drop jumps. Leg stiffness was measured by bilateral and unilateral hopping. A three-repetition maximum squat determined strength. Pearson's correlations and stepwise regression (p ≤ 0.05) determined velocity, step kinematics, and leg muscle performance relationships. CMJ height correlated with and predicted velocity in all intervals (r = 0.40-0.54). The 5BT (5-10 and 0-10 m intervals) and RSI (5-10 m interval) also related to velocity (r = 0.37-0.47). Leg stiffness did not correlate with acceleration kinematics. Greater leg strength related to and predicted lower 0-5 m flight times (r = -0.46 to -0.51), and a longer 0-10 m step length (r = 0.38). Although results supported research emphasizing the value of leg power and strength for acceleration, the correlations and predictive relationships (r(2) = 0.14-0.29) tended to be low, which highlights the complex interaction between sprint technique and leg muscle performance. Nonetheless, given the established relationships between speed, leg power and strength, strength and conditioning coaches should ensure these qualities are expressed during acceleration in field sport athletes.

20.
J Strength Cond Res ; 29(1): 195-205, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25028993

RESUMEN

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. Pearson's 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.


Asunto(s)
Rendimiento Atlético/fisiología , Prueba de Esfuerzo , Movimiento/fisiología , Carrera/fisiología , Adolescente , Adulto , Humanos , Extremidad Inferior/fisiología , Masculino , Distribución Aleatoria , Adulto Joven
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