Name: biomechanical analysis methods to assess professional badminton players' lunge performance
Uploaded: 2019-06-11T13:00:00.000+00:00
Duration: 6 min 36 s
Description: Watch this Scientific Journal Video about Biomechanical Analysis Methods to Assess Professional Badminton Players' Lunge Performance at JoVE.com

This study was sponsored by the National Natural Science Foundation of China (81772423), the K. C. Wong Magna Fund of Ningbo University, and the National Social Science Foundation of China (16BTY085).

The experiment was approved by the Ethics Committee of the Faculty of Sports Science in Ningbo University. All the participants have signed written consents and were told about the requirements and process of the lunge experiment.
1. Gait Laboratory Preparation
<ol>
	<li>When calibrating, remove or cover other potentially reflective items in the volume, avoid the effects of reflections from sunlight, light, and other reflective items on the identification, and ensure a reasonable fluorescent light in the laboratory.</li>
	<li>Plug the dongle into the PC and turn on the motion capture cameras, proprietary tracking software, force platform amplifiers, and the external analog-to-digital converter (ADC).</li>
	<li>Place eight cameras on both sides of the simulated badminton court. Initialize the cameras. Select the Local System node from the System resources pane, and each of the camera nodes will display a green light if selected correctly.
	<ol>
		<li>In the Camera view pane, click Properties to adjust the camera parameters: set the Strobe Intensity to 0.95 to 1, the Threshold to 0.2 - 0.4, the Gain to times 1 (x1), the Grayscale mode to Auto, the Minimum circularity ratio to 0.5, the Max blob height to 50, and select Enable LEDs.</li>
	</ol>
	</li>
	<li>Select Camera in the Perspective pane and put the T-frame on the force plate. In the System resources pane, click the MX Cameras, and select multiple cameras to adjust the parameters.
	<ol>
		<li>In the Setting section, set the parameters of all selected cameras to ensure that data transmitted from each camera can be seen.</li>
	</ol>
	</li>
	<li>Select the 5 marker wand &#38; T-frame in the drop-down menu of the T-frame and select all the cameras.</li>
	<li>Click the split screen button in the upper right corner of the Properties pane. Select the Camera Positions in the Option panel and click the Off button in the drop-down menu of the Extended Frustum.
	<ol>
		<li>Wave the T-frame around the capture volume and stop until the blue light of the camera stops flashing.</li>
	</ol>
	</li>
	<li>Start the calibration, which means the camera continuously collects the data of the markers and displays the collected valid data in the MX Cameras Calibration Feedback toolbar below the Tools pane. Finish the calibration; the progress bar returns to 0%. Ensure the value displayed in the Image Error is less than 0.3.</li>
	<li>Put the T-frame on the force plate (60 x 90 cm) with the axis along the edge of the plate. Ensure that the direction of the T-frame is in accordance with the experimental direction.</li>
	<li>Ensure that the origin of the T-frame is also that of capture volume. Click the Start button from the Set volume origin in the Tool pane to set the origin.</li>
	<li>Ask the subjects to stand on the force plate. Confirm that the direction of the ground reaction vector is upward. Ask the subjects step off the force plate.</li>
	<li>Before starting the trials, click the Force, and select Zero Level. Find the valid data collected in the Wand Count and ensure that each camera collects at least 1,000 frames of valid data.</li>
	<li>Prepare 16 markers of 14 mm in diameter and paste double-sided tape on them in advance.</li>
</ol>
2. Subject Preparation
<ol>
	<li>Let potential subjects fill in a questionnaire survey. Obtain written informed consent from the subjects that fulfill the inclusion criteria. 
	NOTE: Questions: (i) How many years have you played badminton? (ii) Have you participated in professional national level badminton competitions? (iii) Have you suffered any sports injuries and received surgeries? Here, a total of 16 male participants took part in the study: eight professional badminton players and eight amateur badminton players.</li>
	<li>Determine of the subjects meet the criteria. 
	&#8203;NOTE: The criteria include the following items. All participants did not suffer from any injuries in the upper and lower limbs in the six months before the study; the subjects also did not take part in any high-intensity training or competition 2 d before the experiment; for all subjects, the right hand and leg were dominant. Half of the subjects were professional players, half were amateur players; this resulted in eight subjects who are professional badminton players (ages: 23.4 &#177; 1.3 years; height: 172.7 &#177; 3.8 cm; mass: 66.3 &#177; 3.9 kg; badminton-playing years: 9.7 &#177; 1.2 years) and have participated in professional national level competitions, and eight subjects who are amateur badminton players (ages: 22.5 &#177; 1.4 years; height: 173.2 &#177; 1.8 cm; mass: 67.5 &#177; 2.3 kg; badminton playing years: 3.2 &#177; 1.1 years).</li>
	<li>Ask the subjects to wear T-shirts and tight shorts.</li>
	<li>Measure the subjects&#39; height (mm) and weight (kg), as well as the length of both left and right leg (mm) from the superior iliac spine to the ankle internal condyle, the knee widths (mm) from the medial to the lateral knee condyle, and the ankle widths (mm) from the medial to the lateral ankle condyle.</li>
	<li>Mark the skin areas of the anatomical bony landmarks to place the makers.
	<ol>
		<li>Shave body hair as needed and wipe the skin with alcohol. 
		NOTE: The marker locations include spaces bilaterally located to the anterior-superior iliac spine, posterior-superior iliac spine (PSI), lateral thigh (THI), lateral knee (KNE), lateral tibia (TIB), lateral ankle (ANK), heel (HEE), and toe (TOE).</li>
	</ol>
	</li>
	<li>Palpateto identify the anatomical landmarks. Paste the 16 markers on the lower limb.</li>
	<li>Ask the subjects to wear the same brand and series of badminton shoes; then, let them perform a right forward lunge naturally, and ensure the markers on their lower limbs are captured by the cameras.</li>
	<li>Ask the subjects to perform the right forward lunge at a comfortable low speed in the simulated court until they can perform the movement steadily, and instruct them to perform some auxiliary exercises (e.g., marching lunge leg stretch) to warm up.</li>
	<li>Ask the subjects to perform the right forward lunge at a comfortable high speed in the simulated court until they can perform the movement steadily at this speed; then, ask them to put their right leg in the designated area (position B in Figure 1) and underhand strike the shuttlecock to the backcourt (position C).</li>
	<li>Instruct the subjects to perform a maximal right forward lunge from start position A (Figure 1) and underhand strike the shuttlecock to the backcourt (position C), ensuring that their right leg naturally steps on and fully contacts the force platform as they pass, and the subjects must go back to start position A after striking the shuttlecock.</li>
</ol>
3. Static Calibration
<ol>
	<li>Open the Data Management to create a new database. Select the Location, type in the name, and select Based on | Clinical template; then, click on Create.</li>
	<li>Select the subject&#39;s name and click on Open. Click on New patient classification | New patient | New session in order to create the subjects&#39; information.</li>
	<li>At the beginning of the trials, select Session to capture data. Return to the Nexus pane, click on Subjects, and then, click the New subject button. Rename the trials if necessary.</li>
	<li>Click on Go Live, select Split horizontally, and select Graph to view the Trajectory Count.
	<ol>
		<li>Check the number of the markers, which is 16, indicating that there is no unwanted light pollution and all the markers have been captured.</li>
	</ol>
	</li>
	<li>Start to capture static data. In the Subject Preparation section of the toolbar, select Subject Capture and click the Start button. Ask the subjects to stay still and capture 200 frames of images. Click the Stop button.</li>
	<li>Click on Run the reconstruct pipeline to construct markers data. Select Label, identify in the markers&#39; list, and apply the labels to the corresponding markers. Click the Save button. Press the Esc key to exit.</li>
	<li>Click the Subject Preparation and select the Static plug-in gait in the Subject calibration drop-down menu.</li>
	<li>Click Option in the Frame range window that is newly displayed and select Left foot and Right foot in the pop-up window. Select the Start button and, then, save.</li>
</ol>
4. Dynamic Trials
<ol>
	<li>Ask the subject to be in the proper start position.</li>
	<li>After creating the static template, click the Go Live button and select the Capture. Set the Trial Type and the Session in order. Type in a trial name, and the Description is optional.</li>
	<li>Click the Start button in the last option to start capturing and stop after finishing the process. Just repeat the process for each trial.
	<ol>
		<li>In order to conduct experiments, ask the subjects to perform the lunge fast and naturally. Ensure there is a 2 min interval between each trial.</li>
		<li>Ask the subjects the perform the right forward lunge, of which the last step is on the force plate. Require the subjects to perform the movement 6x. If the markers shift or drop, reattach them promptly and capture again.</li>
	</ol>
	</li>
	<li>Select Stop after the subjects perform a maximal right forward lunge and go back to position A (start/finish position).</li>
</ol>
5. Postprocessing
<ol>
	<li>Use special software for postprocessing. Open Data management, double-click the x icon under Files, and click the Run the reconstruct pipeline and labels button; then, click Play under the Perspective pane to play the captured video.</li>
	<li>Drag the pointers on the progress bar under the Perspective pane to set the start and end time of the video.</li>
	<li>Place the cursor within the progress bar, and right-click to select Zoom to Region-of-Interest.</li>
	<li>The identification step is the same as the static identification process. Check the markers and click Fill. Check if all the markers are identified by observing their trajectories. Right-click on unlabeled markers and select Delete all unlabeled.</li>
	<li>Click Start, and the files will be exported in .csv format for postprocessing.</li>
</ol>
6. Data Analysis
<ol>
	<li>Filter kinematic and kinetic data using low-pass Butterworth filters with frequencies at 10 Hz and 25 Hz.</li>
	<li>Calculate the ROMs of the knee and the ankle on sagittal, frontal, and horizontal planes, and obtain the knee and ankle moments through the approach of three-dimensional inverse dynamics. 
	NOTE: The ROMs of the ankle and knee were obtained from the maximum and minimum joint angles on three-dimensional movement planes.</li>
	<li>Divide the lunge into four phases, which include the initial impact peak (I, 5% of the stance), the secondary impact peak (II, 20% of the stance), weight acceptance (III, 40% - 70% of the stance), and the drive-off (IV, 80% of the stance).</li>
	<li>Standardize all joint moment data by using the subjects&#39; weights.</li>
	<li>Collect ground reaction forces and kinematic data at the same time. For each subject, use the mean values of the kinematic and kinetic data of six successful trials for statistical analysis. 
	NOTE: The parameters include the joint (i.e., ankle, knee, and hip) three-dimensional ROMs and the knee and ankle moments.</li>
	<li>Transmit the data to the software for analysis.</li>
</ol>
7. Statistical Analysis
<ol>
	<li>Examine the data of the captured ankle and knee ROMs and the joint moments, using independent-sampled t-tests between the professional players and the amateur players. Use a two-sample t-test to calculate the appropriate number of subjects. Indicate the joints&#39; ROMs and moments by mean values. Set the significance level at p = 0.05.</li>
</ol>

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The authors have nothing to disclose.

One of the disadvantages of most studies analyzing the biomechanical characteristics of the badminton lunging step is that they ignore the skill level of the badminton players performing the lunge. This study divides the subjects into professional players and amateur players to explore the differences in joint ROM and joint moment at different levels when performing a right forward lunge.
As for the ankle joint ROM on the frontal plane, the amateur players exhibited greater ROM than the profes...

Badminton has always been one of the most popular sports in the world. In a game, the frequency of performing lunges is relatively high1. It is of vital importance to master the ability to quickly perform a lunge and return to the start position or move in the other direction2. The lunge not only is crucial to badminton but also is of great importance to tennis, table tennis, and other sports.
The forward lunge has been taken as a function evaluation method for anterior cruciate ligament (ACL) deficiency and knee stability3,4. Studies show that badminton players need both high muscular strength and professional techniques. In general, amateur players pay more attention to technical training than to muscular strength training. If an individual of low-strength ability takes a low-quality training, the training time becomes longer, therefore leading to an overload of the lower limbs and even to a sports injury.
High-intensity training results in a large load on the lower limbs, which may be the cause of sports injuries5. Lower limb injuries account for 60% of the total number of injuries. For both male and female badminton players, the knee and the foot are the most vulnerable parts6,7,8,9. Kinetic data analysis can be used to explain the lower limb injuries of players at different levels. It was reported that professional badminton players have considerable intratendinous flow which rises after repetitive load movements, especially in the patella tendon of the dominant leg.
Reports show that previously conducted research on racquet sports mainly assessed kinematic parameters but focused less on kinetics2,10. When a professional player has played a competition, the pressure is concentrated in their Achilles tendon and anterior knee tendons, especially in the dominant lunge leg5. In racquet sports, clinical analyses of injuries mainly focused on the lower limb, which exceeded 58%, specifically on the knee and ankle5,8,10,11,12,13.
Previous studies have evaluated the physiological indicators of badminton14,15,16 and the features of physical abilities17,18,19,20. Due to these basic features, basic actions on the agility of badminton are proposed to improve the training effect and the on-the-spot performance of the players21,22. Previous studies on badminton focused on different movements or directions of lunge movement without comparing the movement characteristics between professional and amateur badminton players23,24,25,26,27. These differences in dynamics and joint movement make them susceptible to different mechanisms of sports injuries.
The aim of this study is to study the differences in kinematics and dynamics between professional badminton players and amateur badminton players, as well as the range of movement (ROM) of the dominant leg. It is assumed that professional and amateur badminton players show differences in the right forward lunge and that a greater ROM increases the risk of sports injuries.

<table><tbody><tr><td>Motion Tracking Cameras</td><td>Oxford Metrics Ltd., Oxford, UK</td><td></td><td>n= 8</td></tr><tr><td>Valid Dongle</td><td>Oxford Metrics Ltd., Oxford, UK</td><td></td><td>Vicon Nexus 1.4.116</td></tr><tr><td>Force Platform Amplifier</td><td>Kistler, Switzerland</td><td></td><td>n=1</td></tr><tr><td>Force Platform</td><td>Kistler, Switzerland</td><td></td><td>n=1</td></tr><tr><td>Vicon Datastation ADC&amp;nbsp;</td><td>Oxford Metrics Ltd., Oxford, UK</td><td></td><td>-</td></tr><tr><td>T-Frame</td><td>Oxford Metrics Ltd., Oxford, UK</td><td>-</td><td>-</td></tr><tr><td>14 mm Diameter Passive Retro-reflective Marker</td><td>Oxford Metrics Ltd., Oxford, UK</td><td></td><td>n=16</td></tr><tr><td>Double Adhesive Tape</td><td>Oxford Metrics Ltd., Oxford, UK</td><td></td><td>For fixing markers to skin</td></tr><tr><td>Badmionton racket&amp;nbsp;</td><td>Li-ning, China</td><td>BADMINTON RACKET CLUB PLAY BLADE 1000&lt;br/&gt; [AYPL186-4]</td><td>MATERIAL: Standard Grade Carbon Fiber&lt;br/&gt; WEIGHT: 81-84 grams&lt;br/&gt; OVERALL LENGTH: 675mm&lt;br/&gt; GRIP LENGTH: 200mm&lt;br/&gt; BALANCE POINT: 295mm&lt;br/&gt; TENSION: Vertical 20-24 lbs, Horizontal 22-26 lbs</td></tr></tbody></table>

biomechanical analysis methods to assess professional badminton players' lunge performance

Under the condition of simulating a badminton court in the laboratory, this study used the injury mechanism model to analyze the maximal right lunge movements of eight professional badminton players and eight amateur players. The purpose of this protocol is to study the differences in kinematics and joint moment of the right knee and ankle. A motion capture system and force plate were used to capture data of the joint movements of the lower extremity and the vertical ground reaction force (vGRF). Sixteen young men who did not have any sports injuries in the past 6 months took part in the study. The subjects performed a maximal right lunge from the start position with their right foot, stepping on and fully contacting with the force plate, hit the shuttlecock with an underhand stroke to the designated position in the backcourt, and then returned to the start/end position. All subjects wore the same badminton shoes to avoid a difference in impact from different badminton shoes. The amateur players showed a greater range of ankle movement and reverse joint moment on the frontal plane, and a larger internal joint rotation moment on the horizontal plane. The professional badminton players exhibited greater knee moment on the sagittal and frontal planes. Therefore, these factors should be considered in the development of the training program to reduce the risk of sports injuries in knee and ankle joints. This study simulates the real badminton court and calibrates the range of activities of each movement of the subjects so that the subjects complete the experimental action in a natural state with high quality. A limitation of this study is that it does not combine joint load and muscle activity. Another limitation is that the sample size is small and should be expanded in future studies. This research method can be applied to the lower limb biomechanical research of other footwork in the badminton project.

Figure 2&#160;shows the mean vGRF of phases I, II, III, and IV (i.e., the initial impact peak, secondary impact peak, weight acceptance, and drive-off phases, respectively) of the professional players and the amateur players when they performed a lunge. There is no significant difference in phases I, II, and III. However, the vGRF of the professional players is markedly higher than that of the amateur players, indicating a significant difference (<st...

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Biomechanical Analysis Methods to Assess Professional Badminton Players' Lunge Performance

Here, we present a protocol to evaluate the differences in injury mechanisms between professional and amateur players when performing a badminton maximal right lunge movement by analyzing lower limb kinematics.

Under the condition of simulating a badminton court in the laboratory, this study used the injury mechanism model to analyze the maximal right lunge ...

biomechanical-analysis-methods-to-assess-professional-badminton

Research

JoVE Journal

Behavior

10.5K Views.  Ningbo University. Here, we present a protocol to evaluate the differences in injury mechanisms between professional and amateur players when performing a badminton maximal right lunge movement by analyzing lower limb kinematics.

Video: Biomechanical Analysis Methods to Assess Professional Badminton Players' Lunge Performance

Asymmetric Walkway: A Novel Behavioral Assay for Studying Asymmetric Locomotion

Behavioral assays are commonly used for the assessment of sensorimotor impairment in the central nervous system (CNS). The most sophisticated methods for quantifying locomotor deficits in rodents is to measure minute disturbances of unconstrained gait overground (e.g., manual BBB score or automated CatWalk). However, cortical inputs are not required for the generation of basic locomotion produced by the spinal central pattern generator (CPG). Thus, unconstrained walking tasks test locomotor deficits due to motor cortical impairment only indirectly. In this study, we propose a novel, precise foot-placement locomotor task that evaluates cortical inputs to the spinal CPG. An instrumented peg-way was used to impose symmetrical and asymmetrical locomotor tasks mimicking lateralized movement deficits. We demonstrate that shifts from equidistant inter-stride lengths of 20% produce changes in the forelimb stance phase characteristics during locomotion with preferred stride length. Furthermore, we propose that the asymmetric walkway allows for measurements of behavioral outcomes produced by cortical control signals. These measures are relevant for the assessment of impairment after cortical damage.

Here, we present a protocol to quantify precise stepping in rodents. Cortical and the spinal central pattern generator signals are required for precise foot-placement during obstructed locomotion. We report here the novel constrained walking task that directly examines precise stepping behavior.

Behavioral assays are commonly used for the assessment of sensorimotor impairment in the central nervous system (CNS). The most sophisticated methods for ...

Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 &#177; 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters.
With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p &#60;0.05). Also, with motion capture, larger single support time was found WP (p &#60;0.05). With 3-D capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p &#60;0.05). Also, WP yielded smaller moments of force at heel contact and terminal swing along with larger moments at mid-stance of a gait cycle (p &#60;0.05). No changes were found for posture.
NW seems appropriate for promoting a normal gait pattern in older adults. Three-dimensional motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT.

The aim was to substantiate optimal use of data collection techniques for Nordic walking gait and posture analysis. Three-dimensional motion capture should be used during short duration analysis (i.e. single gait cycle), while accelerometry should be employed for longer duration analysis (i.e. repeated cycles) like a 6 Minute Walk Test.

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques ...

Clinical-oriented Three-dimensional Gait Analysis Method for Evaluating Gait Disorder

Three-dimensional gait analysis (3DGA) is shown to be a useful clinical tool for the evaluation of gait abnormality due to movement disorders. However, the use of 3DGA in actual clinics remains uncommon. Possible reasons could include the time-consuming measurement process and difficulties in understanding measurement results, which are often presented using a large number of graphs. Here we present a clinician-friendly 3DGA method developed to facilitate the clinical use of 3DGA. This method consists of simplified preparation and measurement processes that can be performed in a short time period in clinical settings and intuitive results presentation to facilitate clinicians&#39; understanding of results. The quick, simplified measurement procedure is achieved by the use of minimum markers and measurement of patients on a treadmill. To facilitate clinician understanding, results are presented in figures based on the clinicians&#39; perspective. A Lissajous overview picture (LOP), which shows the trajectories of all markers from a holistic viewpoint, is used to facilitate intuitive understanding of gait patterns. Abnormal gait pattern indices, which are based on clinicians&#39; perspectives in gait evaluation and standardized using the data of healthy subjects, are used to evaluate the extent of typical abnormal gait patterns in stroke patients. A graph depicting the analysis of the toe clearance strategy, which depicts how patients rely on normal and compensatory strategies to achieve toe clearance, is also presented. These methods could facilitate implementation of 3DGA in clinical settings and further encourage development of measurement strategies from the clinician&#39;s point of view.

In this study, a clinician-friendly three-dimensional gait analysis method, which was designed to be performed in the rehabilitation clinic, is presented. The method consists of a simplified measurement method and intuitive figures to facilitate clinicians&#39; understanding of the results.

Three-dimensional gait analysis (3DGA) is shown to be a useful clinical tool for the evaluation of gait abnormality due to movement disorders. However, ...

An Inertial Measurement Unit Based Method to Estimate Hip and Knee Joint Kinematics in Team Sport Athletes on the Field

Current athlete monitoring practice in team sports is mainly based on positional data measured by global positioning or local positioning systems. The disadvantage of these measurement systems is that they do not register lower extremity kinematics, which could be a useful measure for identifying injury-risk factors. Rapid development in sensor technology may overcome the limitations of the current measurement systems. With inertial measurement units (IMUs) securely fixed to body segments, sensor fusion algorithms and a biomechanical model, joint kinematics could be estimated. The main purpose of this article is to demonstrate a sensor setup for estimating hip and knee joint kinematics of team sport athletes in the field. Five male subjects (age 22.5 &#177; 2.1 years; body mass 77.0 &#177; 3.8 kg; height 184.3 &#177; 5.2 cm; training experience 15.3 &#177; 4.8 years) performed a maximal 30-meter linear sprint. Hip and knee joint angles and angular velocities were obtained by five IMUs placed on the pelvis, both thighs and both shanks. Hip angles ranged from 195&#176; (&#177; 8&#176;) extension to 100.5&#176; (&#177; 8&#176;) flexion and knee angles ranged from 168.6&#176; (&#177; 12&#176;) minimal flexion and 62.8&#176; (&#177; 12&#176;) maximal flexion. Furthermore, hip angular velocity ranged between 802.6 &#176;&#183;s-1 (&#177; 192 &#176;&#183;s-1) and -674.9 &#176;&#183;s-1 (&#177; 130 &#176;&#183;s-1). Knee angular velocity ranged between 1155.9 &#176;&#183;s-1 (&#177; 200 &#176;&#183;s-1) and -1208.2 &#176;&#183;s-1 (&#177; 264 &#176;&#183;s-1). The sensor setup has been validated and could provide additional information with regard to athlete monitoring in the field.&#160;This may help professionals in a daily sports setting to evaluate their training programs, aiming to reduce injury and optimize performance.

Monitoring athletes is essential for improving performance and reducing injury risk in team sports. Current methods to monitor athletes do not include the lower extremities. Attaching multiple inertial measurement units to the lower extremities could improve monitoring athletes in the field.

Current athlete monitoring practice in team sports is mainly based on positional data measured by global positioning or local positioning systems. The ...

Comparison of Kinetic Characteristics of Footwork during Stroke in Table Tennis: Cross-Step and Chasse Step

The cross-step and chasse step are the basic steps of table tennis. This study presents a protocol to investigate the ground reaction force characteristics between cross-step and chasse step during stroke in table tennis. Sixteen healthy male national level 1 table tennis players (Age: 20.75 &plusmn; 2.06 years) volunteered to participate in the experiment after understanding the purpose and details of the experiment. All participants were asked to hit the ball into the target zone by cross-step and chasse step, respectively. The ground reaction force in the anterior-posterior, medial-lateral, and vertical directions of the participant was measured by a force platform. The key finding of this study was that: the posterior ground reaction force of cross-step footwork (0.89 &plusmn; 0.21) was significantly large (P = 0.014) than the chasse step footwork (0.82 &plusmn; 0.18). However, the lateral ground reaction force of cross-step footwork (-0.38 &plusmn; 0.21) was significantly lower (P &lt; 0.001) than chasse step footwork (-0.46 &plusmn; 0.29) as well as the vertical ground reaction force of cross-step footwork (1.73 &plusmn; 0.19) was significantly lower (P &lt; 0.001) than chasse step footwork (1.9 &plusmn; 0.33). Based on the mechanism of the kinetic chain, the better lower limb dynamic performance of sliding stroke may be conducive to energy transmission and thus bring gain to the swing speed. Beginners should start from the chasse step to hit the ball technically, and then practice the skill of cross-step.

This study presents a protocol to investigate the ground reaction force characteristics between cross-step and chasse step during stroke in table tennis.

The cross-step and chasse step are the basic steps of table tennis. This study presents a protocol to investigate the ground reaction force ...

Assessing Motor Performance in TH-Related Murine Models Using the Ladder Beam Test

A Versatile, Behavioral Method to Investigate Thyroid Hormone Effects on Cerebellar Function

Thyroid hormone (TH) action is essential during the development of the central nervous system, including the cerebellum. In case of TH deficiency in early life such as congenital hypothyroidism, patients display neurological disorders such as cognitive retardation and motor deficits. There are various studies using mouse models with tissue- or cell-specific TH deficiency to investigate the role of TH in the cerebellum. Compared to generalized congenital hypothyroid mice, cerebellar cell-specific TH-deficient mice display milder and subtler ataxic features, making the assessment of motor function difficult when using conventional tests such as the rotarod test. 
Due to the need for an alternative tool to assess motor function in TH-related animal models, we developed a versatile behavioral method called the "ladder beam test," in which we can design the various ladder tests depending on the severity of ataxia in model mice. We utilized transgenic mice expressing a dominant-negative TH receptor specifically in the cerebellar Purkinje cell, a sole output neuron in the cerebellar cortex modulating motor performance. The newly-built ladder beam test successfully detected robust impairments in motor performance in the transgenic mice at a greater level compared to the rotarod test. Disruption of motor learning was also detected in the ladder beam test but not in the rotarod test. The protocol with this novel behavioral apparatus can be applied to other animal models that may show mild ataxic phenotype to examine subtle changes in cerebellar function.

Author Spotlight: Accurately Assessing Thyroid Hormone-Driven Motor Alterations in Mouse

Here we present a protocol for a versatile behavior test developed recently, the ladder beam test. This test has the advantage of detecting subtle cerebellar ataxia caused by a defect of thyroid hormone action in the central nervous system over the conventional behavior tests assessing motor performance.

Thyroid hormone (TH) action is essential during the development of the central nervous system, including the cerebellum. In case of TH deficiency in early ...

Subject-specific Musculoskeletal Model for Studying Bone Strain During Dynamic Motion

Bone stress injuries are common in sports and military trainings. Repetitive large ground impact forces during training could be the cause. It is essential to determine the effect of high ground impact forces on lower-body bone deformation to better understand the mechanisms of bone stress injuries. Conventional strain gauge measurement has been used to study in vivo tibia deformation. This method is associated with limitations including invasiveness of the procedure, involvement of few human subjects, and limited strain data from small bone surface areas. The current study intends to introduce a novel approach to study tibia bone strain under high impact loading conditions. A subject-specific musculoskeletal model was created to represent a healthy male (19 years, 80 kg, 1,800 mm). A flexible finite element tibia model was created based on a computed tomography (CT) scan of the subject&#39;s right tibia. Laboratory motion capture was performed to obtain kinematics and ground reaction forces of drop-landings from different heights (26, 39, 52 cm). Multibody dynamic computer simulations combined with a modal analysis of the flexible tibia were performed to quantify tibia strain during drop-landings. Calculated tibia strain data were in good agreement with previous in vivo studies. It is evident that this non-invasive approach can be applied to study tibia bone strain during high impact activities for a large cohort, which will lead to a better understanding of injury mechanism of tibia stress fractures.

During landing, lower-body bones experience large mechanical loads and are deformed. It is essential to measure bone deformation to better understand the mechanisms of bone stress injuries associated with impacts. A novel approach integrating subject-specific musculoskeletal modeling and finite element analysis is used to measure tibial strain during dynamic movements.

Bone stress injuries are common in sports and military trainings. Repetitive large ground impact forces during training could be the cause. It is ...

Bioengineering

Lower Limb Biomechanical Analysis of Healthy Participants

Biomechanical analysis techniques are useful in the study of human movement. The aim of this study was to introduce a technique for the lower limb biomechanical assessment in healthy participants using commercially available systems. Separate protocols were introduced for the gait analysis and muscle strength testing systems. To ensure maximum accuracy for gait assessment, attention should be given to the marker placements and self-paced treadmill acclimatization time. Similarly, participant positioning, a practice trial, and verbal encouragement are three critical stages in muscle strength testing. The current evidence suggests that the methodology outlined in this article may be effective for the assessment of lower limb biomechanics.

This article introduces a comprehensive experimental methodology on two of the latest technologies available to measure the lower limb biomechanics of individuals.

Biomechanical analysis techniques are useful in the study of human movement. The aim of this study was to introduce a technique for the lower limb ...

Medicine

Influence of Step-Width Manipulation on Running Biomechanics

Step width is a critical factor influencing lower limb biomechanics during running, significantly affecting stability, performance, and injury risk. Understanding these effects is essential for optimizing running performance and minimizing injury risk. This study evaluated the effects of varying step widths on lower limb biomechanics at different running speeds. Thirteen healthy Chinese males (aged 20-24) participated in the study, running at speeds of 3.0 m/s and 3.7 m/s using six distinct step widths: the preferred step width and five variations (reductions of 13% and 6.5%, and increases of 6.5%, 13%, and 25%, based on leg length). Data were collected using a motion capture system and force plates and analyzed through repeated measures ANOVA and correlation tests. The results indicated that wider step widths significantly reduced peak knee abduction moments and hip adduction angles, whereas narrower step widths increased knee joint loading. These findings have important implications for clinicians and runners, suggesting that careful step width selection can help reduce injury risk and enhance running efficiency. This study contributes a new dataset that lays the foundation for future research into the relationship between step width and running biomechanics and serves as a reference for training and rehabilitation practices.

The present protocol outlines an experimental setup designed to investigate the influence of step width manipulation on running biomechanics using a motion capture system. The objective is to expand relevant datasets and examine the effects of varying step widths on the kinematic chain of the human lower limb.

Step width is a critical factor influencing lower limb biomechanics during running, significantly affecting stability, performance, and injury risk. ...

Postural Organization of Gait Initiation for Biomechanical Analysis Using Force Platform Recordings

Gait initiation (GI), the transient phase between orthograde posture and steady-state locomotion, is a functional task and an experimental paradigm that is classically used in the literature to obtain insight into the basic postural mechanisms underlying body motion and balance control. Investigating GI has also contributed to a better understanding of the physiopathology of postural disorders in elderly and neurological participants (e.g., patients with Parkinson&#39;s disease). As such, it is recognized to have important clinical implications, especially in terms of fall prevention.
This paper aims to provide scholars, clinicians, and higher education students information on the material and method developed to investigate GI postural organization via a biomechanical approach. The method is based on force platform recordings and the direct principle of mechanics to compute the kinematics of the center of gravity and center of pressure. The interaction between these two virtual points is a key element in this method since it determines the conditions of stability and whole-body progression. The protocol involves the participant initially standing immobile in an upright posture and starting to walk until the end of an at least 5 m track.
It is recommended to vary the GI velocity (slow, spontaneous, fast) and the level of temporal pressure - gait may be initiated as soon as possible after the deliverance of a departure signal (high level of temporal pressure) or when the participant feels ready (low level of temporal pressure). Biomechanical parameters obtained with this method (e.g., duration and amplitude of anticipatory postural adjustments, step length/width, performance, and stability) are defined, and their computation method is detailed. In addition, typical values obtained in healthy young adults are provided. Finally, critical steps, limitations, and significance of the method with respect to the alternative method (motion capture system) are discussed.

This paper describes the material and method developed to investigate the postural organization of gait initiation. The method is based on force platform recordings and on the direct principle of mechanics to compute center of gravity and center of pressure kinematics.

Gait initiation (GI), the transient phase between orthograde posture and steady-state locomotion, is a functional task and an experimental paradigm that ...