Weerawat Limroongreungrat

Different Sagittal Angles and Moments of Lower Extremity Joints during Single-leg Jump Landing among Various Directions in Basketball and Volleyball Athletes

[Purpose] The purpose of this study was to assess the sagittal angles and moments of lower extremity joints during single-leg jump landing in various directions. [Subjects] Eighteen male athletes participated in the study. [Methods] Participants were asked to perform single-leg jump-landing tests in four directions. Angles and net joint moments of lower extremity joints in the sagittal plane were investigated during jump-landing tests from a 30-cm-high platform with a Vicon™ motion system. The data were analyzed with one-way repeated measures ANOVA. [Results] The results showed that knee joint flexion increased and hip joint flexion decreased at foot contact. In peak angle during landing, increasing ankle dorsiflexion and decreasing hip flexion were noted. In addition, an increase in ankle plantarflexor moment occurred. [Conclusion] Adjusting the dorsiflexion angle and plantarflexor moment during landing might be the dominant strategy of athletes responding to different directions of jump landing. Decreasing hip flexion during landing is associated with a stiff landing. Sport clinicians and athletes should focus on increasing knee and hip flexion angles, a soft landing technique, in diagonal and lateral directions to reduce risk of injury.

An Instrumented Wheel System for Measuring 3-D Pushrim Kinetics During Racing Wheelchair Propulsion

The purpose of this study was to design and validate an instrumented wheel system (IWS) that can measure 3-dimensional (3-D) pushrim forces during racing wheelchair propulsion. Linearity, precision, and percent error were determined for both static and dynamic conditions. For the static condition, the IWS demonstrated a high linearity (0.91 ≤ slope ≤ 1.41) with less than 2.72% error rate. Under dynamic loading, the IWS provided the well-matched measurement forces with the predicted values from the inverse dynamics method (0.96 ≤ slope ≤ 1.07) with less than 4.32% error rate. The results revealed that the IWS developed in the study can be used to measure 3-D pushrim reaction forces with acceptable accuracy. This was the first instrumented wheel device that can register 3-D pushrim forces during racing wheelchair propulsion. With the available kinetic information of the 3-D pushrim forces, the upper extremity joint reaction forces could be determined.

Immediate video feedback on ramp, wheelie, and curb wheelchair skill training for persons with spinal cord injury.

We hypothesized that the effects of immediate video feedback (IVF) on training ramp, wheelie, and curb wheelchair skills for persons with spinal cord injury (SCI) would be equivalent to or better than the traditional wheelchair skill training. Participants were manual wheelchair users with recent SCI (thoracic 1-lumbar 1) who were matched (9 pairs) on motor function level, age, and sex and randomly assigned to a control group (conventional training) or an experimental group (IVF training). Participants learned three wheelchair skills and then went through the wheelchair skill competency test, retention test, and transfer test. Paired t-tests were used to examine the differences in training time (minutes), spotter intervention needed (counts), and successful rate in performance between the two groups. A 2 (groups) x 3 (skills) x 3 (tests) repeated-measures analysis of variance and Bonferroni adjustment test were used to examine differences between groups on wheelchair skills and tests. No differences were found between two groups in training times (minutes) on three wheelchair skills (experimental vs control: ramp 14.92 +/- 5.80 vs 11.69 +/- 7.85; wheelie 17.79 +/- 6.03 vs 19.92 +/- 13.42; and curb 38.35 +/-23.01 vs 48.59 +/- 15.21). This study demonstrated that IVF for training manual wheelchair skills may produce similar results as the conventional training and may be an alternative training method for wheelchair skills.

Can segmental model reductions quantify whole-body balance accurately during dynamic activities?

When investigating whole-body balance in dynamic tasks, adequately tracking the whole-body centre of mass (CoM) or derivatives such as the extrapolated centre of mass (XCoM) can be crucial but add considerable measurement efforts. The aim of this study was to investigate whether reduced kinematic models can still provide adequate CoM and XCoM representations during dynamic sporting tasks. Seventeen healthy recreationally active subjects (14 males and 3 females; age, 24.9±3.2years; height, 177.3±6.9cm; body mass 72.6±7.0kg) participated in this study. Participants completed three dynamic movements, jumping, kicking, and overarm throwing. Marker-based kinematic data were collected with 10 optoelectronic cameras at 250Hz (Oqus Qualisys, Gothenburg, Sweden). The differences between (X)CoM from a full-body model (gold standard) and (X)CoM representations based on six selected model reductions were evaluated using a Bland-Altman approach. A threshold difference was set at ±2cm to help the reader interpret which model can still provide an acceptable (X)CoM representation. Antero-posterior and medio-lateral displacement profiles of the CoM representation based on lower limbs, trunk and upper limbs showed strong agreement, slightly reduced for lower limbs and trunk only. Representations based on lower limbs only showed less strong agreement, particularly for XCoM in kicking. Overall, our results provide justification of the use of certain model reductions for specific needs, saving measurement effort whilst limiting the error of tracking (X)CoM trajectories in the context of whole-body balance investigation.

Elastic therapeutic tape: do they have the same material properties?

[Purpose] Elastic therapeutic tape has been widely used for rehabilitation and treatment of sports injuries. Tapes with different elastic properties serve different treatment purposes with inappropriate tension reducing tape effectiveness. Many tapes are available in the market, but studies on tape properties are limited. The aim of this study was to examine the material properties of elastic therapeutic tape. [Subjects and Methods] Brands of elastic therapeutic tape included KinesioTex®, ATex, Mueller, 3M, and ThaiTape. The Material Testing System Insight® 1 Electromechanical Testing Systems was used to apply a tensile force on elastic therapeutic tape. Ten specimens of each brand were tested. Stress, load, and Young’s modulus at 25%, 50%, 75%, 100%, and maximum point were collected. One-way analysis of variance with post hoc testing was used to analyze tape parameters. [Results] Maximum elongation and Young’s modulus at all percentages were significantly different between brands. There were no differences in maximum load and maximum stress. [Conclusion] Mechanical properties are different for commercial elastic therapeutic tapes. Physiotherapists and other clinicians should be aware of mechanical tape properties to correctly apply kinesio tape.

Knee Muscular Control During Jump Landing in Multidirections

Background Jump landing is a complex movement in sports. While competing and practicing, athletes frequently perform multi-planar jump landing. Anticipatory muscle activity could influence the amount of knee flexion and prepare the knee for dynamic weight bearing such as landing tasks. Objectives The aim of the present study was to examine knee muscle function and knee flexion excursion as athletes naturally performed multi-direction jump landing. Materials and Methods Eighteen male athletes performed the jump-landing test in four directions: forward (0°), 30° diagonal, 60° diagonal, and lateral (90°). Muscles tested were vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), semitendinosus (ST), and biceps femoris (BF). A ViconTM 612 workstation collected the kinematic data. An electromyography was synchronized with the ViconTM Motion system to quantify dynamic muscle function. Repeated measure ANOVA was used to analyze the data. Results Jump-landing direction significantly influenced (P < 0.05) muscle activities of VL, RF, and ST and knee flexion excursion. Jumpers landed with a trend of decreasing knee flexion excursion and ST muscle activity 100 ms before foot contact progressively from forward to lateral directions of jump landing. Conclusions A higher risk of knee injury might occur during lateral jump landing than forward and diagonal directions. Athletes should have more practice in jump landing in lateral direction to avoid injury. Landing technique with high knee flexion in multi-directions should be taught to jumpers for knee injury prevention.

The effect of virtual reality-based balance training on motor learning and postural control in healthy adults: a randomized preliminary study

BackgroundAdults with sedentary lifestyles seem to face a higher risk of falling in their later years. Several causes, such as impairment of strength, coordination, and cognitive function, influence worsening health conditions, including balancing ability. Many modalities can be applied to improve the balance function and prevent falling. Several studies have also recorded the effects of balance training in elderly adults for fall prevention. Accordingly, the aim of this study is to define the effect of virtual reality-based balance training on motor learning and postural control abilities in healthy adults.MethodsFor this study, ten subjects were randomly allocated into either the conventional exercise (CON) or the virtual reality (VR) group. The CON group underwent physical balance training, while the VR group used the virtual reality system 4 weeks. In the VR group, the scores from three game modes were utilized to describe the effect of motor learning and define the learning curves that were derived with the power law function. Wilcoxon Signed Ranks Test was performed to analyze the postural control in five standing tasks, and data were collected with the help of a force plate.ResultsThe average score was used to describe the effect of motor learning by deriving the mathematical models for determining the learning curve. Additionally, the models were classified into two exponential functions that relied on the aim and requirement skills. A negative exponential function was observed in the game mode, which requires the cognitive-motor function. In contrast, a positive exponential function was found in the game with use of only the motor skill. Moreover, this curve and its model were also used to describe the effect of learning in the long term and the ratio of difficulty in each game. In the balance performance, there was a significant decrease in the center of pressure parameters in the VR group, while in the CON group, there was a significant increase in the parameters during some foot placements, especially in the medio-lateral direction.ConclusionThe proposed VR-based training relies on the effect of motor learning in long-term training though different kinds of task training. In postural analysis, both exercise programs are emphasized to improve the balance ability in healthy adults. However, the virtual reality system can promote better outcomes to improve postural control post exercising.Trial registration Retrospectively registered on 25 April 2018. Trial number TCTR20180430005

Upper Extremity Kinematics during Free Throw Shooting of Thai Wheelchair Basketball Players

Wheelchair basketball (WCB) is one of the fastest growing competitive team sports. To score points, free-throw shooting (FTS) is the easiest shot since it is an uncontested shot. Although previous studies have been investigated kinematic of FTS, kinematics of upper extremity has never been reported in Thai WCB players. Understanding upper extremity kinematics is valuable since it can help improve shooting performance. Thus, the purpose of this study was to study upper extremity kinematic during free throws of advanced WCB players. Five male WCB athletes (meanage = 27 + 2.9 yrs, meanweight 61 + 4.2 Kg) volunteered in the study. Participants were divided into two groups: high class (4-4.5 points) and low class (3 – 3.5 points). Seven retroreflective markers were placed on the right side of second metacarpophalangeal joint, the fifth metacarpophalangeal joint, and the radial and ulna styloid processes, the medial and lateral epicondyles and acromion process. Three video cameras were simultaneously recorded FTS motion at the sampling frequency of 30 Hz and synchronized by the light switch. Raw coordinate data were filtered with 4th order Butterworth with a cut-off frequency of 4 Hz. Each participant performed FTS for 10 trials which two successful trials of clean shot were averaged and analyzed. Upper extremity angles including shoulder, elbow and wrist were obtained. The Mann-Whitney U test was employed to determine statistical significance between the groups. The results showed that the high class had a greater range of motion of shoulder and elbow than the low class group whereas the low class group used a larger range of motion than the high group. Since the low class group used smaller range of motion at the shoulder and elbow joint, they may compensate at the wrist joint. Nevertheless, no statistical differences of upper extremity angles between the two groups were found (p<0.05). Due to the small sample size, future investigation with larger sample size is warranted.

Fundamental Locomotive Activity Time Efficiency with Differently Positioning Drive-Axis Wheelchairs Among Elderly: 2388

This study examined time efficiency in wheelchair locomotive activities among four different wheelchairs propelled by elders with arms and/or legs. Sixteen elder manual wheelchair users propelled her/his own wheelchair and three wheelchairs (the main drive-axis wheels positioning in front, middle, and rear, respectively) in the test of seven wheelchair locomotive activities of daily living. A Mixed-Model ANOVA and Bonferroni post hoc test (p < .05) were employed to determine the time efficiency among four wheelchairs and three groups. The results demonstrated better time efficiency resulted from propelling the mid drive-axis and/or rear drive-axis wheelchairs; using arms and legs simultaneously propelling wheelchairs was more time efficient than using the arms or legs only in the selected locomotive activities.