Asian Journal of Sports Medicine
Volume:2 Issue: 4, Dec 2011

Vitamin D deficiency is a worldwide epidemic, with well known impacts on calcium metabolism and bone health, but increasingly recognized associations with chronic health problems such as bowel and colonic cancer, arthritis, diabetes and cardiovascular disease. In recent years in the Sports Medicine literature, there has been an increased focus on the potential impact that inadequate Vitamin D levels may have on athletic performance. In the early 20th Century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and while remaining limited, evidence is accumulating to support this view. Muscle structure and function is recognised to play a key role in athletic performance, and both cross-sectional and longitudinal studies allude to a functional role for Vitamin D in muscle. The identification of the Vitamin D receptor in muscle tissue provides a direct pathway for Vitamin D to impact upon Skeletal Muscle structure and function. This review focuses on the current understanding of the action of Vitamin D within skeletal muscle tissue, and the potential impact on performance.

The purpose of this study was to estimate the dominant handgrip strength and its correlations with some hand and arm anthropometric variables in 101 randomly selected Indian inter-university female volleyball players aged 18-25 years (mean age 20.52 ± 1.40) from six Indian universities. Three anthropometric variables, i.e. height, weight, BMI, two hand anthropometric variables, viz. right and left hand width and length, four arm anthropometric variables, i.e. upper arm length, lower arm length, upper extremity length, upper arm circumference and dominant right and non-dominant handgrip strength were measured among Indian inter-university female volleyball players by standard anthropometric techniques. The findings of the present study indicated that Indian female volleyball players had higher mean values in eleven variables and lesser mean values in two variables than their control counterparts, showing significant differences (P<0.032-0.000) in height (t=2.63), weight (t=8.66), left hand width (t=2.10), left and right hand length (t=9.99 and 10.40 respectively), right upper arm length (t=8.48), right forearm length (t=5.41), dominant (right) and non-dominant (left) handgrip strength (t=9.37 and 6.76 respectively). In female volleyball players, dominant handgrip strength had significantly positive correlations (P≤0.01) with all the variables studied. It may be concluded that dominant handgrip strength had strong positive correlations with all the variables studied in Indian inter-university female volleyball players.

There is a decrease in quadriceps muscle strength in subjects with patellofemoral pain syndrome. Various types of strengthening exercises of the quadriceps are done as part of its management, but the effect of isotonic eccentric quadriceps muscle exercises on patellofemoral pain syndrome has not been studied. Hence the aim of this exploratory pilot study was to evaluate the effect of eccentric quadriceps training in patients with patellofemoral pain. Twenty patients (12 female and 8 male, mean ages, 27.50 +/- 6.6 years) with patellofemoral pain syndrome were treated. The eccentric training of the quadriceps was given using a BTe Primus machine. The main outcome measures used were percentage time on target as shown by the BTe primus machine, SF-36 Health questionnaire and patellofemoral pain severity scale. Statistical analysis was performed using SPSS 13. All the outcome measures showed significant improvements (P<.05). Percentage time on target improved with a mean difference of 23.6, the SF-36 questionnaire showed an improvement in physical component score, mental component score and bodily pain with a mean difference of 10.9, 2.6 and 29.2 respectively and pain score when taken using patellofemoral severity scale also improved with a mean difference of 3.4. Isotonic eccentric training of quadriceps muscles was found to be effective in reducing pain and improving the functional status of patients with patellofemoral pain syndrome and can be suggested as part of the treatment.

The objectives of this study include: (1) Determination of the attenuation of strike acceleration that Tae Kwon Do sparring safety pads provide from kicks from Olympic style TKD fighters, (2) The sex and weight differentiation in acceleration achieved within the thorax model with the roundhouse kicks. This prospective, observational study utilized 15 Olympic style fighters from an "elite" team kicking a water core heavy bag thorax model with roundhouse kicks. The model was fitted with a tri-axial accelerometer (GCDC, model X250-2) to measure g acceleration from strikes to the bag. The bag was kicked in three, 10 kick phases by all subjects: kicks without padding; kicks with hogu on heavy bag, and kicks with hogu and instep guards on feet. The g acceleration readings were recorded in all phases. Kolmogorov-Smirnov failed for all variables. There were 8 female subjects: median age 14 years, median weight 53.4 kg and 7 male subjects: median age 17 years, median weight 70.45 kg. The ANOVA on ranks of the acceleration from kicks against the bag achieved significance, P≤0.001. Spearman rank order correlation between the weights of players and acceleration of strike against the hogu without and with insteps pads was significant, P=0.035/r=0.54 and P=0.018/r=0.59, respectively. Heavier and male subjects tend to produce more force in strikes. Protective chest guard reduces acceleration to the thorax model, but the utility of instep guards is questionable.

The aim of this study was to investigat the offensive efficiency of the professional handball players forming the front and rear lines. Our investigation was carried out on four matches (final, semi-finals and classifying match) at the 19th male Handball World Championship "Tunisia 2005". Finalist teams were Tunisia, France, Croatia, and Spain. Matches were recorded using 5 digital camcorders (SONY, DCL, and TRV 130E). Number of passes and the length of the attacks were determined by software "STUDIO 9". Speed of the ball at the different shootings was calculated by REGAVI software, version 2.57, 2004. Work was dissociated according to 2 variables namely axes and lines. Players of lateral axes (A4) and front basis (L1) were shorter and thinner than those of the central axis (A3) and rear basis (L2). No differences were observed between lines and axes in age. The analysis of the total shootings to the goal shows that the players of lines and axes present very close values in each team, excepting the Croatian L2 compared to the Tunisian L2. Players of the rear Croatian basis present also a number of attacks concluded by a non-successfully cadred shooting greater than all other groups. In the Spanish group, a significant difference among number of passes concluded by a non-successfully cadred shooting between lines, and front basis vs central axis was noted. No significant difference was found between lines and axes in the Croatian team. Regarding the velocity of shooting, excepting the Croatian team, no differences were found between lines and axes of the other teams. No differences were also noted in the attack duration between lines and axes in Croatian and Tunisian teams. In the Spanish team, duration of attacks concluded by a cadred shooting was most important when finished by an L2 or an A3 player. The present results demonstrate that finalist teams were found to be clearly characterized by L2 and A3 players taller and weightier than those of L1 and A4. Organized attack was generally concluded by shooting done by an L2 or an A4 player and the shooting velocity did not significantly determine the offensive efficiency.

To determine if functional performance deficits are present in athletes with functional ankle instability (FAI) compared to healthy athletes using various functional performance tests. Sixty two athletes (mean age-21.7±1.8years; height-168.2±9.1cm; weight-63.8±11.0kg) participated in this case control study. Athletes were divided into two groups: athletes with FAI (FAI group, n=31) and healthy athletes (Non-FAI group, n=31). The FAI group was further divided into two subgroups: FAI with giving way (FAI-GW), FAI with no giving way (FAI-NGW). Functional performance was assessed with the single-limb hopping test, figure-of-8 hop test, side-hop test, single-limb hurdle test, square hop test and single hop test. Significant differences (P<0.05) were observed for all the functional performance tests (FPTs) except the single hop test between FAI and Non-FAI groups; between FAI-GW, FAI-NGW and Non-FAI groups. Additionally, the involved limb performed significantly worse (P<0.05) than the contra-lateral uninvolved limb of the FAI-GW group for the above-mentioned FPTs. Significant functional performance deficits were observed in the FAI group in all tests except single hop test with greater deficits observed in the FAI-GW group. Hence, these tests can be used to determine the presence of FAI. However no deficits were identified for the test involving sagittal plane functional activities suggesting that this test can not be used as a criterion to discriminate individuals with FAI. It was further ascertain.

The purpose of the present study was to evaluate effects of regular practice of sun salutation on muscle strength, general body endurance and body composition. Subjects (49 male and 30 female) performed 24 cycles of sun salutation, 6 days a week for 24 weeks. Upper body muscle strength was determined by 1 repetition maximum (1RM) for bench press and shoulder press technique. Back and leg dynamometry was used to assess strength of back and leg muscles. General body endurance was evaluated by push-up and sit-up tests. Body composition was assessed by noting % body fat by using bioelectric impedance analysis. Perceived intensity of exercise by subjects was noted by Borg scale. Muscle strength by bench press showed significant increase in male (29.49±9.70 to 36.12±9.09 Kg, P<0.001) and female (10.5±4.42 to 13.16±4.44 Kg, P<0.001) subjects. Strength by shoulder press also increased (males; 22.96±9.57 Kg to 26.53±11.05 Kg, P<0.001, females; 6.83±2.78 to 8.83±3.87, P<0.001). Endurance by push-ups & sit-ups showed similar findings in male (19.0±9.58 to 21.98±8.98, P < 0.001 and 24.92±10.41 to 29.84±12.64, p <0.001 respectively) and female (14.66±6.80 to 18.56±6.97 and 13.16±7.75 to 19.23±8.25, P<0.001 respectively) subjects. A significant decrease in body fat percent was observed only in female (27.68±5.46 to 25.76±4.72, P<0.001) but not in male subjects. BMI significantly decreased in both the groups (z=4.37, P<001 and t=5.41, P<0.001 respectively). From our observations we conclude that sun salutation can be an ideal exercise to keep oneself in optimum level of fitness.

This study was performed to introduce and evaluate the potential of kinematic magnetic resonance imaging (KMRI) using a high-field open-magnet magnetic resonance (MR) system. We attempted to perform KMRI of healthy volunteer's lumbar spine and knee in the lateral position and ankle in the supine position utilizing the superconducting, horizontally opened, 1.2 T MR system (OASIS, HITACHI, Tokyo, Japan). For the KMRI of the lumbar spine, the volunteer had to lie on one side while maintaining maximally anteflexed, neutral, and maximally retroflexed positions and remain still for the duration of the acquisition time for each posture. In the same way, KMRI of the knee was performed with the volunteer's knee flexed at 0º, 30º, 60º, 90º, and 120º in the lateral position, and KMRI of the ankle was performed with the volunteer's ankle in maximally dorsiflexed, neutral, and maximally plantarflexed positions while lying in the supine position. We could acquire higher quality kinematic MR images than those acquired using low-field MR systems. The spinal canal, intervertebral discs and foramina, and facet joints in lumbar spine KMRI; the ligaments, menisci and patellofemoral joint in knee KMRI; and the tibiotalar articulation and peroneal tendon in ankle KMRI were clearly depicted. The results of our pilot trial indicated that a superconducting horizontally opened, 1.2 T MR system offers high-quality KMRI images and can be utilized for the kinematic diagnosis and evaluation of sports injuries.

The review by Dr. Halabchi, et al is an excellent summary and reiteration of the importance of the addition of ECG screening to the pre-participation exam (PPE) for athletic competition. To pioneer this campaign in Asia, is a noble endeavor and is no small feat. As highlighted by this review, the general consensus for enforcing ECG as a requisite for participation varies greatly by the governing bodies making the suggestions and the demographic which they represent.