Postural profile of female basketball players and differences among playing positions

OBJECTIVE

Basketball players often display poor balance and increased injury rates when compared to other athletic categories. Therefore, the relationship between postural control and injury risks in basketball athletes requires investigation. The purpose of this study was to: (a) establish a postural profile of elite women basketball players, (b) compare postural control of the different playing positions to detect the vulnerability of postural balance, and (c) attempt to understand the reasons underlying these differences.

PATIENTS AND METHODS

30 elite female basketball players (aged 21.4±2.3 years) were assigned to three groups according to their playing positions (n=10 guards; n=10 forwards; n=10 centers). A one-way analysis of variance was performed to determine differences between balance test variables under three conditions (static, dynamic antero-posterior and medio-lateral). When a significant main effect was observed, Tukey's post-hoc multiple comparisons tests were used to determine statistical significance. Associations between balance and morphological variables, muscle strength and power were assessed using Pearson's correlation coefficient.

RESULTS

Results reveal that basketball players had better postural control than previously studied handball players and non-athletes, but they are more dependent on vision than other categories. When comparing postural controls of playing position, centers show greater vulnerability [Y mean (OE)] than forwards: p<0.001; or guards: p<0.01), due to morphological factors (body mass r=-0.80, height r=-0.68, and lower limb length r=-0.63, and specific power r=-0.40).

CONCLUSIONS

Therefore, coaches and strength and conditioning specialists should give specific focus to improving lower limb strength and power in centers and taller basketball players to mitigate against injury risks related to postural control.

Effects of high-intensity interval training and plyometric exercise on the physical fitness of junior male handball players

OBJECTIVE

This study analyzed the effects of high intensity interval training (HIIT) combined with plyometric exercise on the physical fitness of junior male handball players.

PATIENTS AND METHODS

Subjects (age ~17 years) were randomly divided between experimental (n=17) and control (n=15) groups. During the 8-week intervention, the experimental group replaced a part of their regular regimen by HIIT, combined with plyometric exercise. Assessments in both groups before and after the intervention included: squat jump (SJ), countermovement jump (CMJ), sprint performance (5 m, 10 m, 20 m and 30 m), change of direction tests (Illinois modified test [Illinois-MT] and T-half test), 20-m shuttle run, and repeated sprint T-test.

RESULTS

The two-way analyses of variance revealed significant group-time interactions (all p<0.05), favoring the intervention group in 5 m, 10 m, 20 m and 30 m sprint (d=0.33, 8.3%; d=0.52, 7.6%; d=0.57, 6.8%; and d=0.58, 8.8%, respectively), T-half (d=0.25, 5.1%), Illinois-MT (d=0.47, 4.2%), SJ and CMJ (d=0.34-0.39, 34-4-34.9%), repeated sprint T-test best time, mean time and total time (d=0.83, 6.9%; d=0.62, 7.4%; and d=0.61, 7.2%, respectively), 20 meter shuttle run test aerobic maximum speed and predicted maximal oxygen intake (d=0.36, 7.5%; d=0.19, 9.4%, respectively).

CONCLUSIONS

HIIT combined with plyometrics can aid in the development of physical fitness abilities, which are extremely important to junior male handball players.

Ground surface nature can influence visual information contribution in postural control

BACKGROUND

In sport, the nature of ground surface is likely to influence the contribution of visual information on postural control. Boxing and wrestling are respectively practiced on firm and soft ground surfaces. The aim was to compare the postural control of boxers with that of wrestlers on stable (firm) and unstable (soft and dynamic) ground surfaces, with and without deprivation of vision.

METHODS

Fifteen male international boxers and 15 male international wrestlers presenting the same anthropometrics characteristics and the same number of years of sports practice were recruited. Spatiotemporal parameters of displacement of the center of feet pressure (COP) were measured on a force platform in static (firm and foam surfaces with eyes open and eyes closed) and dynamic conditions (medio/lateral and antero-posterior directions with eyes open and eyes closed).

RESULTS

The results mainly showed a significant vision × group interaction in the antero-posterior direction for the dynamic postural condition (P<0.017). This indicated that the contribution of visual information was greater for the boxers than for the wrestlers in challenging condition (P=0.030).

CONCLUSIONS

Further studies are needed to confirm whether the nature of ground surface influences the contribution of visual information, which can be, in turn, affected by the specificity of motor skills.

Association of anthropometric qualities with vertical jump performance in elite male volleyball players

AIM

The objective of this study was to examine the association between physical and anthropometric profiles and vertical jump performance in elite volleyball players.

METHODS

Thirty-three elite male volleyball players (21±1 y, 76.9±5.2 kg, 186.5±5 cm) were studied. Several anthropometric measurements (body mass, stature, body mass index, lower limb length and sitting height) together with jumping height anaerobic power of counter movement jump with arm swing (CMJarm) were obtained from all subjects. Forward stepwise multiple linear regression analysis was performed to determine if any of the anthropometric parameters were predictive of CMJarm.

RESULTS

Anaerobic power was significantly higher (P≤0.05) in the tallest players relative to their shorter counterparts. A significant relationship was observed between CMJarm and lower limb length (r2=0.69; P<0.001) and between the lower limb length and anaerobic power obtained with CMJarm (r2=0.57; P<0.01). While significantly correlated (P≤0.05) with CMJarm performance, stature, lower limb length/stature and sitting height/stature ratios were not significant (P>0.05) predictors of CMJarm performance.

CONCLUSION

This study demonstrates that lower limb length is correlated with CMJarm in elite male volleyball players. The players with longer lower limbs have the better vertical jump performances and their anaerobic power is higher. These results could be of importance for trained athletes in sports relying on jumping performance, such as basketball, handball or volleyball. Thus, the measurement of anthropometric characteristics, such as stature and lower limb length may assist coaches in the early phases of talent identification in volleyball.

Relationships between maximal anaerobic power of the arms and legs and javelin performance

AIM

The aim of this study was to examine relationships between maximal anaerobic power, as measured by leg and arm force-velocity tests, estimates of local muscle volume and javelin performance.

METHODS

Ten trained national level male javelin throwers (mean age 19.6+/- 2 years) participated in this study. Maximal anaerobic power, maximal force and maximal velocity were measured during leg (Wmax-L) and arm (Wmax-A) force-velocity tests, performed on appropriately modified forms of Monark cycle ergometer. Estimates of leg and arm muscle volume were made using a standard anthropometric kit.

RESULTS

Maximal force of the leg (Fmax-L) was significantly correlated with estimated leg muscle volume (r=0.71, P<0.05). Wmax-L and Wmax-A were both significantly correlated with javelin performance (r=0.76, P<0.01; r=0.71, P <0.05, respectively). Maximal velocity of the leg (Vmax-L) was also significantly correlated with throwing performance (r=0.83; P<0.001).

CONCLUSION

Wmax of both legs and arms were significantly correlated with javelin performance, the closest correlation being for Wmax-L; this emphasizes the importance of the leg muscles in this sport. Fmax-L and Vmax-L were related to muscle volume and to javelin performance, respectively. Force-velocity testing may have value in regulating conditioning and rehabilitation in sports involving throwing.

Comparison of Muscle Mechanical and Histochemical Properties Between Young and Elderly Subjects

We examined age-related human muscle fiber changes and their relation with maximal power scaled to muscle volume (specific power). Fiber type distribution and cross sectional area (CSA) were determined from m. vastus lateralis in 7 young (YS; 29.6 +/- 5 years) and 7 elderly subjects (ES; 74.3 +/- 3 years). Muscle volume and mean CSA of the thigh were anthropometrically measured. Muscle power was assessed by a series of accelerations on a cycle ergometer. Specific power was 35 % lower in ES than YS. Area ratios of IIa/I and IIx/I fibers were lower in ES than YS. By including single fiber power data from the literature to the present results, the decline in the specific power between YS and ES was 34 %, when data of both IIa and IIx fibers were considered. The decrease of the specific power with age on the whole muscle would be compatible with the age-induced changes in the muscle histochemical characteristics.