International SportMed Journal - Volume 14, Issue 2, 2013
Volume 14, Issue 2, 2013
Lower limb joint sense, muscle strength and postural stability in adolescent Taekwondo practitioners : original research articleSource: International SportMed Journal 14, pp 44 –52 (2013)More Less
Background : Taekwondo (TKD) is a popular combat sport renowned for its kicking techniques. With repeated practice, it may enhance the sensorimotor performance and balance of its practitioners.
Research question : This study aimed (1) to compare the effects of short-term and long-term TKD training on the lower limb joint proprioception, muscle strength and balance performance of adolescents, and (2) to explore the relationships among these three outcome measures.
Type of study : Observational study.
Methods : Thirty-one adolescents including long-term (n=11), short-term (n=10), and non-practitioners (n=10) of TKD participated in the study. The knee joint position sense, isokinetic strength of the quadriceps and hamstrings, and sway in prolonged single-leg standing were measured.
Results : Long-term TKD practitioners made significantly smaller errors in the knee joint repositioning test than the control group (p<0.01). No significant difference was found in the body-weight-adjusted isokinetic peak torque of the quadriceps (p>0.01) or hamstrings (p>0.01) among the three groups. Both short- and long-term TKD practitioners swayed significantly slower than control participants while standing on one leg (p<0.01). The accuracy of knee joint angle repositioning was significantly correlated with sway velocity (r = 0.499, p<0.01).
Conclusions : More than one year of TKD training can improve single-leg standing balance. The better postural stability demonstrated by long-term TKD practitioners may be associated with better knee joint position sense rather than knee muscle strength. Physiotherapists may therefore suggest long-term TKD exercise for adolescents to improve balance.
Effects of taekwondo kicks on head accelerations and injury potential : a pilot study : original research articleSource: International SportMed Journal 14, pp 53 –66 (2013)More Less
Background : In taekwondo (TKD), the incidence of concussion is four times greater than in American gridiron football. Biomechanical studies of concussion in taekwondo are scarce.
Research question : To assess the effect of head impact biomechanics as a result of taekwondo kicks.
Type of study : Between-groups design.
Methods : Two male (22.0±0.0 years, 184±0.0cm, 81.3±1.8 kg) and two female (0.0±2.8 years, 171.0±1.4 cm, 63.0±5.2 kg) elite taekwondo athletes participated in this study. Head linear acceleration (RLA) and head injury criterion (HIC) data were collected from five different head kicks randomly performed five times. A Hybrid II Crash Dummy head (H2D) was instrumented with a tri-axial accelerometer.
Results : Significant differences were found between kicks in RLA (eta2=3.8) and HIC (eta2=4.6) in the men and women (RLA, eta2=4.5 and HIC, eta2=4.7). Post-hoc analyses showed differences in RLA between the jump back kick (61.6±31.0 g) and clench axe kick (33.3±11.1 g) in males (ES=0.9). HIC analysis revealed differences between the jump back kick (556.8±679.2) and jump hook kick (191.0±37.2) (ES=0.7) and in head velocity between the turning kick (5.0±0.5 m.s-1) and jump hook kick (3.2±1.3 m.s-1, ES=1.1) in the males. In the females, there was a difference between the jump back (HIC: 236.8±104.3) and clench axe kicks (22.2±11.2) (ES=1.2) and in foot velocity between the turning (15.7±1.2 m.s-1) and clench axe kicks (9.1±2.3 m.s-1) (ES=1.2).
Conclusions : Previous research reported RLA values of 67.0 g (HIC=167) in boxing compared to 72.8 g (HIC=667) in TKD. These high magnitudes of injury-related measures highlight the need for the implementation of more safety precautions.
Source: International SportMed Journal 14, pp 67 –76 (2013)More Less
Background : Flexibility training is an often overlooked, but nevertheless important component of overall fitness, health and athletic performance and is positively impacted by flexibility training. Emerging technologies, including the Wii Fit, offer an alternative to traditional flexibility training. To date however, no research has examined the impact of the flexibility component of the Wii Fit on upper and lower body flexibility.
Research question : The purpose of the study was to determine the impact of a four week Wii Fit yoga training session on flexibility and heart rate.
Type of study : A pre-test post-test control group design was used.
Methods : Healthy, moderately active participants (N = 32) were randomly assigned to either a training (N=14) or control (N=18) group, where the training group completed four weeks of Wii flexibility training and flexibility test practice, for three sessions a week. Flexibility was assessed for both the control group and training groups prior to and after the training sessions, using the sit and reach and shoulder flexibility tests.
Results : Significant improvements in both upper and lower body flexibility were noted for the Wii Fit users, while the control group showed no changes in flexibility over the testing period.
Conclusions : Data suggest that the flexibility training provided by the Wii Fit yoga exercises have a significant impact on upper and lower body flexibility, suggesting the Wii Fit can be effectively utilised as part of overall flexibility training.
The effect of functional fatigue on static and dynamic balance in female athletes : original research articleSource: International SportMed Journal 14, pp 77 –85 (2013)More Less
Background : Balance is one of the critical factors that affects athletes' performances, and is recognized to have a central role in sport injury prevention, while the effect of functional fatigue on static and dynamic balance has not been properly investigated.
Research question : To understand the effect of functional fatigue on static and dynamic balance in female athletes.
Methods : Fifteen female basketball players (age: 16.1 ± 1.1 years; weight: 53.1 ± 6.7 kg; height: 164.1 ± 4.6 cm) with no orthopaedic problems volunteered to participate in the study. They performed subsequently pre-One-Foot Balance Test (OFBT), pre-Star Excursion Balance Test (SEBT), fatigue protocol, post-SEBT, and post-OFBT. The SEBT and OFBT protocol were used to measure the amount of dynamic and static balance, respectively. A functional fatigue protocol that lasted 20 minutes was performed to tire the subjects. The amount of perceived fatigue was measured with rating of perceived excursion (RPE) values.
Results : Although the effect of functional fatigue was not significant on the dynamic balance of the subjects, the dynamic balance performance between directions was found to be significant (P <0.001). In addition, the result showed that fatigue had a significant effect on the subjects' static balance (P = 0.019).
Conclusion : As static balance is one of the factors that affects athletic performance and is also used during the rehabilitation tasks; the finding may help to prevent fatigue-related problems, such as balance perturbation of athletes during conditioning and rehabilitation, and consequently in preventing injuries.
The effects of 16 weeks of exercise on metabolic parameters, blood pressure, body mass index and functional autonomy in elderly women : original research articleSource: International SportMed Journal 14, pp 86 –93 (2013)More Less
The present study analysed the effects of 16 weeks of an exercise programme on blood lipids, blood pressure, anthropometry and functional autonomy of elderly women. Fifty-four elderly women were divided into two groups: experimental group (EG) (68.9 ± 6.8 years), who underwent a 16-week training programme, and a control group (CG) (66.6 ± 6.0 years). All metabolic parameters changed over the 16-week period for the EG: total cholesterol (228.0±34.8 to 190.5±22.5 mg/dl), HDL (48.4±4.9 to 53.4±6.0 mg/dl), LDL (162.4±16.6 to 115.2±11.9 mg/dl), VLDL, (31.5±4.0 to 29.7±4.4 mg/dl), triglycerides (127.5 ± 53.5 to 105.1 ± 30.2 mg/dl) and glucose (94.8±11.3 to 85.9±5.9 mg/dl). CG showed changes in total cholesterol (220.0±30.5 to 198.3±29.1 mg/dl) only. For blood pressure, EG improved after training with respect to systolic blood pressure (145.3±4.3 to 136.2±10.9 mmHg) and diastolic blood pressure (95.8±8.6 to 85.9±8.6 mmHg), while the CG showed improvement in systolic blood pressure (147.8±12.2 to 140.1±12.8 mmHg) only. Body mass index was lower after training for the EG (29.0±5.2 to 28.4±5.1 kg/m2). For functional autonomy, EG improved performance in the five tests evaluated: 10m walk test (C10m) (10.4±4.5 to 7.9±2.3 m), rising from a seated position (LPS) (12.4 ± 4.3 to 10.5 ± 3.0 s), rising from the prone position (LPDV) (7.9±3 to 6.2±3.6 s), rising from a chair and moving around the house (LCLC) (63.8±16.5 to 55.8±12.3 s) and testing to put on a shirt (VTC) (18.9±8.7 to 15.6±9 s). The authors conclude that a multiple-component physical activity training programme improves blood lipids, blood pressure, BMI and measures of functional autonomy in older women.
Source: International SportMed Journal 14, pp 94 –98 (2013)More Less
The assessment of skin temperature (Tsk) in athletic therapy and sports medicine research is an extremely important physiological outcome measure. Various methods of recording Tsk, including thermistors, thermocouples and thermocrons are currently being used for research purposes. These techniques are constrained by their wires limiting the freedom of the subject, slow response times, and/or sensors falling off. Furthermore, as these products typically are directly attached to the skin and cover the measurement site, their validity may be questionable. This manuscript addresses the use and potential benefits of using thermal imaging (TI) in sport medicine research. Non-contact infrared TI offers a quick, non-invasive, portable and athlete-friendly method of assessing Tsk. TI is a useful Tsk diagnostic tool that has potential to be an integral part of sport medicine research in the future. Furthermore, as the technique is non-contact it has several advantages over existing methods of recording skin temperature.