Youlian Hong

A Systematic Review on Ankle Injury and Ankle Sprain in Sports

AbstractThis article systematically reviews epidemiological studies on sports injury from 1977 to 2005 in which ankle injury was included. A total of 227 studies reporting injury pattern in 70 sports from 38 countries were included. A total of 201 600 patients were included, with 32 509 ankle injuries. Ankle injury information was available from 14 098 patients, with 11 847 ankle sprains. Results show that the ankle was the most common injured body site in 24 of 70 included sports, especially in aeroball, wall climbing, indoor volleyball, mountaineering, netball and field events in track and field. Ankle sprain was the major ankle injury in 33 of 43 sports, especially in Australian football, field hockey, handball, orienteering, scooter and squash. In sports injuries throughout the countries studied, the ankle was the second most common injured body site after the knee, and ankle sprain was the most common type of ankle injury. The incidence of ankle injury and ankle sprain was high in court games and team sports, such as rugby, soccer, volleyball, handball and basketball. This systematic review provides a summary of the epidemiology of ankle injury in sports.

Biomechanics of Supination Ankle Sprain A Case Report of an Accidental Injury Event in the Laboratory

Ankle sprain is the most common injury in sports, but the mechanism of injury is not clear. Injury mechanisms can be studied through many different approaches. Over the years, ankle kinematics has been studied during simulated subinjury or close-to-injury situations, that is, sudden simulated ankle spraining motion on inversion platforms. Because these tests did not induce real injury, they could only somewhat suggest the ankle kinematics during an ankle sprain injury. The most direct way is to investigate real injuries using biomechanical measuring techniques. However, it is obviously unethical to do experiments where test subjects are purposefully injured. Nevertheless, in rare cases, accidents may occur during biomechanical testing. It has been shown that video sequences from sports competitions can provide limited but valuable information for qualitative ankle injury analysis. However, quantitative biomechanics analysis of sport injury is not easy as it requires calibrated multiview video sequences. This study presented an accidental supination ankle sprain injury that occurred in a laboratory under a high-speed video and plantar pressure capturing setting.

Effects of load carriage on heart rate, blood pressure and energy expenditure in children

Fifteen male primary school children, aged 10 years, were selected to carry school bags of 10, 15 and 20% of their own body weights, where 0% body weight was used as a control. Maximum oxygen uptake ([Vdot]O2max) tests were conducted on a motorized treadmill using a continuous incremental protocol. During the load carrying test, subjects walked on a treadmill at 1.1 m s−1 for 20 min at each load condition. Blood pressures were measured before, immediately following, and at 3 and 5 min after every trial. Heart rate and expired [Vdot]O2 were recorded before, during and 5 min after walking using a cardiopulmonary function system. The results showed a significant difference in oxygen uptake, energy expenditure and the recovery of blood pressure rise for between 10 and 20% body weight load conditions. The carrying weight of a school bag for children could be recommended as 10% of body weight because it was not significantly different from 0% load in the metabolic cost.

Changes in muscle strength, endurance, and reaction of the lower extremities with Tai Chi intervention

This study examines the effects of a 16-week Tai Chi (TC) training program on the muscle strength, endurance, and reaction time of the lower extremities of elderly people. A total of 40 elderly individuals (aged 60 years) completed the study. They were divided into two groups: the TC group (11 men and 11 women) underwent a supervised TC exercise program for 16 weeks, while the control group (9 men and 9 women) received general education for a comparable time period. Pre- and post-intervention measurements were conducted. An isokinetic dynamometer was used to measure the maximum concentric strength and dynamic endurance of the knee flexors and the extensors, and the maximum concentric strength of the ankle plantarflexors and dorsiflexors. The neuromuscular response of the rectus femoris, semitendinosus, gastrocnemius, and anterior tibialis muscles was measured by the onset latency to sudden perturbations using an electromyography system. After 16 weeks, the TC group showed a 19.9% increase in muscle strength of the knee flexors (p<.000) that was significantly greater than that in the control group (p=.046). There was also a significant decrease in semitendinosus muscle latency (6.6%, p=.014) that was significantly shorter than that in the control group (p=.042). No significant training effects were found in other measures. These results suggest that improving biomechanical characteristics of lower extremity muscles may need longer TC intervention for elderly people.

Estimating the complete ground reaction forces with pressure insoles in walking

This study presented a method to estimate the complete ground reaction forces from pressure insoles in walking. Five male subjects performed 10 walking trials in a laboratory. The complete ground reaction forces were collected during a right foot stride by a force plate at 1000Hz. Simultaneous plantar pressure data were collected at 100Hz by a pressure insole system with 99 sensors covering the whole plantar area. Stepwise linear regressions were performed to individually reconstruct the complete ground reaction forces in three directions from the 99 individual pressure data until redundancy among the predictors occurred. An additional linear regression was performed to reconstruct the vertical ground reaction force by the sum of the value of the 99 pressure sensors. Five other subjects performed the same walking test for validation. Estimated ground reaction forces in three directions were calculated with the developed regression models, and were compared with the real data recorded from force plate. Accuracy was represented by the correlation coefficient and the root mean square error. Results showed very good correlation in anterior-posterior (0.928) and vertical (0.989) directions, and reasonable correlation in medial-lateral direction (0.719). The root mean square error was about 12%, 5% and 28% of the peak recorded value. Future studies should aim to generalize the methods or to establish specific methods to other subjects, patients, motions, footwear and floor conditions. The method gives an extra option to study an estimation of the complete ground reaction forces in any environment without the constraints from the number and location of force plates.

Biomechanics of Tai Chi: A review

Tai Chi Chuan is a favourite form of exercise throughout the world and has drawn increasing research interest from international scientists. Biomechanical research into Tai Chi has grown substantially and has provided evidence of the beneficial effects of Tai Chi exercise on health, fitness, and prevention of falls. This paper reviews studies that have explored the biomechanical aspects of Tai Chi, such as balance, kinematics, kinetics, strength, and neuromuscular activities.

Lower-extremity Gait Kinematics on Slippery Surfaces in Construction Worksites

PURPOSE The purpose of this study was to investigate the lower-extremity kinematics when walking on potentially slippery surfaces in simulated construction worksite environments. METHODS A survey was conducted to select two types of footwear, two floorings, and four contaminants to represent the local construction worksite environments, making 16 simulated conditions. A mechanical slip-resistance test was conducted to evaluate the slipping potential of the 16 conditions by the value of the dynamic coefficient of friction. The 16 conditions were classified into three groups by slipping potential. Fifteen harnessed Chinese male subjects were instructed to walk and avoid slips on each of the 16 simulated 5-m walkways 10 times at their natural cadence. The movements in the sagittal plane were videotaped, digitized, and analyzed by a motion analysis system. Gait pattern parameters were obtained. Lower-extremity kinematic data were time-normalized from foot strike (0% stance) to take-off (100% stance) and were extracted from foot strike to midstance (50% stance) at 10% stance intervals. RESULTS ANOVA showed that with increased slipping potential, changes in gait pattern parameters included increased stance and stride time, shortened stride length, decreased propagation speed, and gentle heel strike. In lower-extremity kinematic parameters, significant differences were found mainly at the ankle joint rather than the knee joint. CONCLUSION Strategies to prevent slips included increased stance and stride time, shortened stride length, decreased propagation speed, and gentle heel strike. The ankle joint played the most important role in adaptation strategy. Such strategy included reducing range of motion, maintaining a stiff joint, and achieving flatfoot landing or a plantarflexed ankle joint during the first 10% stance.

Comparison of plantar loads during treadmill and overground running

OBJECTIVES The objective of this study is to compare plantar loads during treadmill running and running on concrete and grass surfaces. DESIGN Crossover study design was used in the study. METHODS A total of 16 experienced heel-to-toe runners participated in the study. Plantar loads data were collected using a Novel Pedar insole sensor system during running on the treadmill, concrete, and grass surfaces at 3.8m/s running speed and then analyzed. RESULTS Compared with running on the two other surfaces, treadmill running showed a lower magnitude of maximum plantar pressure and maximum plantar force for the total foot, maximum plantar pressure at two toe regions, and maximum plantar force for the medial forefoot region and two toe regions (p<0.0017). Treadmill running also showed a longer absolute contact time at two toe regions compared with running on the other two surfaces (p<0.0017). CONCLUSIONS Treadmill running is associated with a lower magnitude of maximum plantar pressure and a lower maximum plantar force at the plantar areas. These results suggest that the plantar load distribution in treadmill running is not the same as the plantar load distribution in running on overground surfaces. Treadmill running may be useful in early rehabilitation programs. Patients with injuries in their lower extremities may benefit from the reduction in plantar loads. However, the translation to overground running needs investigation.

Cushioning and lateral stability functions of cloth sport shoes

In this study, we evaluated the protective functions of cloth sport shoes, including cushioning and lateral stability. Twelve male students participated in the study (mean ± s: age 12.7 ± 0.4 years, mass 40.7 ± 5.9 kg, height 1.50 ± 0.04 m). Cloth sport shoes, running shoes, basketball shoes, cross-training shoes, and barefoot conditions were investigated in random sequence. Human pendulum and cutting movement tests were used to assess cushioning performance and lateral stability, respectively. For cushioning, the running shoes (2.06 body weight, BW) performed the best, while the cross-training shoes (2.30 BW) and the basketball shoes (2.37 BW) both performed better than the cloth sport shoes (2.55 BW) and going barefoot (2.63 BW). For the lateral stability test, range of inversion–eversion was found to be from 3.6 to 4.9°, which was far less than that for adult participants (> 20°). No significant differences were found between conditions. All conditions showed prolonged durations from foot-strike to maximum inversion (66–95 ms), which was less vigorous than that for adult participants ( < 40 ms) and was unlikely to evoke intrinsic stability failure. In conclusion, the cloth sport shoe showed inferior cushioning capability but the same lateral stability as the other sports shoes for children.

A three-pressure-sensor (3PS) system for monitoring ankle supination torque during sport motions

This study presented a three-pressure-sensor (3PS) system for monitoring ankle supination torque during sport motions. Five male subjects wore a pair of cloth sport shoes and performed 10 trials of walking, running, cutting, vertical jump-landing and stepping-down motions in a random sequence. A pair of pressure insoles (Novel Pedar model W, Germany) was inserted in the shoes for the measurement of plantar pressure at 100Hz. The ankle joint torque was calculated by a standard lower extremity inverse dynamic calculation procedure with the data obtained by a motion capture system (VICON, UK) and a force plate (AMTI, USA), and was presented in a supination/pronation plane with an oblique axis of rotation at the ankle joint. Stepwise linear regression analysis suggested that pressure data at three locations beneath the foot were essential for reconstructing the ankle supination torque. Another group of five male subjects participated in a validation test with the same procedure, but with the pressure insoles replaced by the 3PS system. Estimated ankle supination torque was calculated from the equation developed by the regression analysis. Results suggested that the correlation between the standard and estimated data was high (R=0.938). The overall root mean square error was 6.91Nm, which was about 6% of the peak values recorded in the five sport motions (113Nm). With the good estimation accuracy, tiny size and inexpensive cost, the 3PS system is readily available to be implanted in sport shoe for the estimation and monitoring of ankle supination torque during dynamic sport motions.