Kong, Pui Wah

It is commonly believed that massage can reduce muscle stiffness and is desirable for recovery from exercise. However, the effect massage on muscle stiffness following eccentric exercises is currently unknown. This study aimed to examine the effect of postexercise massage on passive muscle stiffness over a five-day period. A randomised cross-over study design was adopted. After 40 minutes of downhill running, 18 male recreational runners had one leg received a 16-minute massage and the contralateral leg received a 16-minute sham ultrasound treatment. Passive stiffness for four leg muscles (rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius) was assessed using myotonometry at baseline, immediately post-run, post-treatment, 24, 48, 72, and 96 hours post-run. A 2 (treatment) × 7 (time) mixed ANOVA was conducted with a robust procedure on the myotonometry data of each leg muscle to examine the effect of treatment on stiffness. Passive stiffness for all muscles changed over time but no treatment effect was found. Stiffness increased at 24 hours post-run and remained elevated from baseline levels for up to 96 hours across all four muscles. Significant treatment × time interaction was only found in the tibialis anterior but no post-hoc differences were identified. Passive stiffness of major leg muscles increased after a bout of unaccustomed eccentric exercise and remained elevated for up to four days post-exercise. Compared with the placebo treatment, post-exercise massage had no beneficial effect in alleviating altered muscle stiffness in major leg muscles.

This study aimed to quantify the break shot characteristics and identify their significance in predicting the game outcomes in 9-ball tournaments. The break shots of 275 frames (241 men’s, 34 women’s) of professional tournaments were analyzed from two aspects: (1) cue ball position, represented by the distance between the cue ball and the table center, and (2) ball distribution, indicated by the standard deviation of Voronoi cell areas determined from all remaining balls on the table. Spearman correlation and binary logistic regression were utilized to identify associations and to predict the frame outcomes, respectively. Results showed that the more balls falling into the pockets during the break, the more clustered the remaining balls (rs = 0.232, p < 0.001). The closer the cue ball ending toward the table center, the more balls potted in the visit immediately after the break (rs = −0.144, p = 0.027). Neither cue ball position nor ball distribution could predict table clearance or winning of a frame. In conclusion, pocketing more balls during the break is associated with more clustered balls remaining on the table. Parking the cue ball near the table center after the break can facilitate potting more balls immediately after.

The purpose of this study was to examine the effects of low-Dye tape on comfort and ground reaction forces (GRF) in flat-footed female runners. A randomized cross-over study was conducted on 15 flat-footed female recreational runners. Participants ran at three speeds (9, 10, 11 km/h) under two conditions: low-Dye and sham taping. Comfort level was assessed using a 150-mm visual analog scale. GRF data were collected using an instrumented treadmill. Stance time, peak forces, and loading rates were extracted. Low-Dye taping showed a lower comfort level (low-Dye, 63.8 (24.3) mm, sham 122.0 (16.0) mm, mean difference [95% confident intervals], -58.2 [68.2, 48.2] mm, p < 0.001). For all biomechanical variables, there was no interaction (taping condition a speed) effect or difference between taping conditions. As running speed increased, there was a decrease in stance time (p < 0.001) and increase in loading rate (p = 0.009), impact peak (p = 0.004), active peak (p < .001), breaking peak (p < 0.001), propulsive peak (p < 0.001), medial peak (p < 0.001), and lateral peak (p < 0.001). Compared with sham taping, application of low-Dye taping was less comfortable but did not alter running ground reaction forces among flat-footed female runners.

Patellofemoral pain (PFP) is a common injury in runners, especially females, but it is unclear if the kinematic risk factors between the sexes are the same. This study aimed to identify the kinematics of healthy and injured recreational runners with PFP in both sexes. High-speed videos of treadmill running gait in 56 subjects (14 in each injured and non-injured male and female group) were analysed using the Kinovea software. Three kinematic variables associated with PFP were extracted at midstance: knee midstance position, knee flexion angle, and hip adduction angle. Compared with healthy controls, injured females ran with knees more medially positioned (Left p = 0.008, Right p < 0.001), while injured males ran with less knee flexion (Left p = 0.006, Right p = 0.007). These findings suggest that kinematic risk factors associated with PFP are sex-specific.

The loadsol® wireless in-shoe force sensors can be useful for in-field measurements. However, its accuracy is unknown in the military context, whereby soldiers have to carry heavy loads and walk in military boots. The purpose of this study was to establish the validity of the loadsol® sensors in military personnel during loaded walking on flat, inclined and declined surfaces. Full-time Singapore Armed Forces (SAF) personnel (n = 8) walked on an instrumented treadmill on flat, 10° inclined, and 10° declined gradients while carrying heavy loads (25 kg and 35 kg). Normal ground reaction forces (GRF), perpendicular to the contact surface, were simultaneously measured using both the loadsol® sensors inserted in the military boots and the Bertec instrumented treadmill as the gold standard. A total of eight variables of interest were compared between loadsol® and treadmill, including four kinetic (impact peak force, active peak force, impulse, loading rate) and four spatiotemporal (stance time, stride time, cadence, step length) variables. Validity was assessed using Bland–Altman plots and 95% Limits of Agreement (LoA). Bias was calculated as the mean difference between the values obtained from loadsol® and the instrumented treadmill. Results showed similar force-time profiles between loadsol® sensors and the instrumented treadmill. The bias of most variables was generally low, with a narrow range of LoA. The high accuracy and good agreement with standard laboratory equipment suggest that the loadsol® system is a valid tool for measuring normal GRF during walking in military boots under heavy load carriage.

Table tennis is a sport that is enjoyed by many, including those with physical and intellectual disabilities. This scoping review summarised the current test protocols for assessing table tennis technical proficiency in individuals with disabilities. Relevant articles were searched through four databases (Scopus, PubMed, SPORTDiscus, and Web of Science) covering three key aspects: disability, table tennis, and technical proficiency. The search resulted in 14 studies included for data extraction, covering physical impairments, intellectual disability, and development coordination disorder. Almost all studies (93%) were conducted on well-trained para-table tennis athletes competing in high-level competitions. There exist protocols to assess service accuracy and stroke accuracy, hand–eye coordination, quality of specific skills and ball control, functional reach, and trunk rotation. The forehand topspin and backhand topspin drives were tested the most. Table tennis robots and video cameras are the common equipment used. Moving forward, future research should develop technical proficiency tests for players across all competency levels. The skill assessment criteria and scoring methods should be standardised and clearly explained. The validity and reliability of tests should be established. Lastly, there is great potential in using artificial intelligence to enhance the assessment of table tennis proficiency in individuals with disabilities.

This study examined 1) the perception of running shoes between China (Beijing) and Singapore, and 2) whether running shoe preference depended on assessment methods. One hundred (n=50 each country) Chinese males subjectively evaluated four shoe models during running using two assessment procedures. Procedure 1 used a Visual Analogue Scale (VAS) to assess five perception variables. Procedure 2 was a ‘Head-to-head’ comparison of two shoes simultaneously (e.g. left foot: A, right foot: B) to decide which model was preferred. VAS scores were consistently higher in Beijing participants (P<.001), indicating a higher degree of liking. Singapore participants used the lower end but a wider range of the 15-cm scale for shoe discrimination. Moderate agreement was seen between the VAS and 'Head-to-head' procedures, with only 14 out of 100 participants matched all 6 pairwise comparisons (median=4 matches). Footwear companies and researchers should be aware that subjective shoe preference may vary with assessment methods.

This study aimed to examine the influence of court surface on foot loading when executing typical basketball tasks. Thirteen male basketball players performed three basketball-related tasks: Layup, jump shot, and maximal effort sprint on wooden and asphalt courts. In-shoe plantar loading was recorded during the basketball movements and peak force (normalised to body weight) was extracted from eight-foot regions. Perceptions of discomfort at the ankle, knee, and back were surveyed using a 10-cm visual analogue scale. Landing from a layup on the wooden court resulted in elevated peak forces at the hallux (p = 0.022) and lesser toes (p = 0.007) compared with asphalt court. During the sprint acceleration step, higher peak forces were observed at the hallux (p = 0.048) and medial forefoot (p =0.010) on wooden court. No difference between court surfaces was found for perception ratings at the ankle, knee, or back. These results suggested that players can experience greater impact forces at the toes and medial forefoot when performing basketball tasks on the more compliant wooden court than asphalt courts.

Previous studies generally selected one foot to classify participants into groups with different foot types and then analyzed the running or walking biomechanics for one limb. Such approach may have neglected the possible differences in foot morphology and gait between two limbs. This study aimed to compare the foot morphological characteristics and running kinematics of the lower extremities between the left and right limbs among a group of healthy, asymptomatic runners. Forty-four participants [20 females, 24 males; age 25.1 (6.5) years old; height 167.2 (7.0) cm; body mass 62.8 (8.1) kg] were recruited. Foot morphological characteristics were measured for both feet, and bilateral running kinematics were analyzed with 2D video analysis. No significant between-limb differences were found in the foot dimensions, hallux valgus (bunion) angle, or navicular drop (all p > 0.05). On the other hand, several kinematic variables were significantly different between the left and right limbs during running, including the peak foot eversion (p = 0.014), peak knee flexion (p = 0.002), and peak hip adduction (p < 0.001). The results indicate that runners with similar morphological characteristics between the left and right feet can display between-limb gait asymmetry during running. Researchers and practitioners should be aware of the potential between-limb asymmetry in running kinematics and foot morphology. Future studies should avoid arbitrarily analyzing one limb to represent a runner’s gait or foot morphology.