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Kinematics Change In Countermovement Jumps With Additional Loads, Jana Holder, Isabella Fessl, Eric Harbour, Hermann Schwameder Jul 2023

Kinematics Change In Countermovement Jumps With Additional Loads, Jana Holder, Isabella Fessl, Eric Harbour, Hermann Schwameder

ISBS Proceedings Archive

The aim of this study was to investigate the effect of sex and additional load during countermovement jumps on hip, knee, and ankle joint kinematics. For this purpose, a total of 25 female and male participants performed barbell-loaded countermovement jumps with up to 80% of body mass. No significant main effect of sex on any of the kinematic parameters was found. The additional load resulted in a significant decrease in hip, knee, and ankle joint angles in the sagittal plane and an increase of the absolute performance time. Significant differences were also found in the frontal and transverse plane kinematics. …

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Investigating The Performance Of Cycling And Hockey Helmet Liner Materials In Mitigating Impacts At Lower Speeds During Free Falls, Shrivatsa Hegde, Meilan Liu, Carlos Zerpa Jul 2023

Investigating The Performance Of Cycling And Hockey Helmet Liner Materials In Mitigating Impacts At Lower Speeds During Free Falls, Shrivatsa Hegde, Meilan Liu, Carlos Zerpa

ISBS Proceedings Archive

This study examined the performance of helmets made of expanded polystyrene (EPS) and expanded propylene (EPP) in mitigating linear impacts over three consecutive drop trials at 16 impact speeds ranging from 0.93 to 3.96 m/s. It was found that EPS, a liner material used in cycling helmets, had lower capacity of mitigating linear impact acceleration and captured a larger compressed area of impact than the EPPs, liner materials used for hockey helmets. EPS and EPPs all experienced some degrees of loss in their capacities to mitigate acceleration after the initial impact. All tested materials had no statistically significant difference in …

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Energy Flow And Ground Reaction Force Predictors Of Bat Swing Speed During Pitched Ball Batting In Professional Baseball Players, Jason Hashimoto, D. Taylor La Salle, Avery Takata, Arnel Aguinaldo, Kyle Wasserberger Jul 2023

Energy Flow And Ground Reaction Force Predictors Of Bat Swing Speed During Pitched Ball Batting In Professional Baseball Players, Jason Hashimoto, D. Taylor La Salle, Avery Takata, Arnel Aguinaldo, Kyle Wasserberger

ISBS Proceedings Archive

The purposes of this study are to determine how mechanical energy is absorbed, generated, and transferred during baseball hitting for professional athletes. This study also aims to identify which ground reaction force and energy flow variables influence bat speed. The findings of this study suggest that energy flows from the trunk to the lead leg as the pelvis rotates towards the pitcher. The results of this study emphasize the crucial role of the back leg and trunk during acceleration as well as eccentric contraction of muscles in the lead leg and trunk to decelerate during follow-through. Training strategies that improve …

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Ankle And Knee Joint Functional Indices During A Drop Jump: Exploring Performance Relationships, Michael H. Haischer, Nayun Ahn, Nora Mckeough, William R. Adler, Kristof Kipp Jul 2023

Ankle And Knee Joint Functional Indices During A Drop Jump: Exploring Performance Relationships, Michael H. Haischer, Nayun Ahn, Nora Mckeough, William R. Adler, Kristof Kipp

ISBS Proceedings Archive

The purpose of this study was to describe ankle and knee joint functional indices during a drop jump task and characterize the associations to performance outcomes (jump height, ground contact time, and reactive strength index). Forty-five collegiate or club level athletes performed five drop jumps off a 12-inch box while motion capture and ground reaction force data were recorded. Time-series joint kinematics and kinetics were used to calculate joint functional indices, reported as relative percentages of strut-, spring-, damper-, and motor-like mechanical behavior. Correlation and regression analyses uncovered several significant associations between joint functional indices and performance outcomes. Greater motor-like …

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What Would It Take To Break The World Record In The Men’S Triple Jump, Philip Graham-Smith, Paul Brice Jul 2023

What Would It Take To Break The World Record In The Men’S Triple Jump, Philip Graham-Smith, Paul Brice

ISBS Proceedings Archive

The purpose of this study was to bring together 30 years of athlete support and applied research into the horizontal jumps and develop a strategy for an elite athlete to challenge the World Record which has stood for over 27 years. Data on an elite triple jumper who has jumped over 18m was collected in a Diamond League competition and in training. Approach speed, phase distances, technical analysis and anthropometrical data were utilised to develop an interactive 7 segment model from which a new World Record was reconstructed. This study demonstrates a process of how to utilise biomechanical data and …

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Pose Estimation Or Manual Digitising: Can Automating Technologies Change The Current In-Field Assessment Of High Jump?, Molly Goldacre Jul 2023

Pose Estimation Or Manual Digitising: Can Automating Technologies Change The Current In-Field Assessment Of High Jump?, Molly Goldacre

ISBS Proceedings Archive

Biomechanists spend significant time completing the time-consuming task of manually digitising 2D videos to derive kinematic spatiotemporal parameters. Recent advances in 2D pose estimation models (PEMs) hold promise for automating the determination of parameters in sport. This study developed an automated PEM digitising and analysis pipeline (AAP) for high jump. We investigated differences in four spatiotemporal and joint angle outputs from traditional manual processing pipelines (MAP) and the AAP using paired t-tests, intra-class correlations and effect size analysis. Statistical analysis revealed that knee angles derived from the MAP and AAP were not different, whereas penultimate foot contact time and both …

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Usage And Acceptabiity Of Data Normalization In Baseball Pitching, Kevin A. Giordano, Adam Barrack, Kyle Wasserberger, William Murrah, Andy Karduna, Lori Michener Jul 2023

Usage And Acceptabiity Of Data Normalization In Baseball Pitching, Kevin A. Giordano, Adam Barrack, Kyle Wasserberger, William Murrah, Andy Karduna, Lori Michener

ISBS Proceedings Archive

To account for athletes of different sizes, kinetic values are commonly ‘normalized’ by dividing by mass and/or height. However, the creation of a ratio variable requires certain statistical assumptions to be met. The purpose of this study was to determine if elbow valgus torque predicted by pitching velocity is influenced by the normalization method using regression model comparison with normalized torque values. Both mass and mass*height normalization satisfied the correlation and zero intercept assumptions. Results did not agree between analysis methods that elbow valgus torque could be predicted with pitching velocity at the α = 0.05 level, indicating caution should …

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Coordination And Coordination Variability In Trail Running, Matteo Genitrini, Julian Fritz, Hermann Schwameder Jul 2023

Coordination And Coordination Variability In Trail Running, Matteo Genitrini, Julian Fritz, Hermann Schwameder

ISBS Proceedings Archive

Trail running is an emerging endurance discipline. Unveiling differences in motor adaptation between more (MP) and less (LP) proficient athletes represents the first step to I) standardize injury prevention protocols and II) optimize training. The aim of this work was to compare MP and LP trail runners for coordination and coordination variability (CV). Twenty athletes carried out a field test wearing a full body motion capture system. Coordination and CV were assessed for three couplings: I) knee-ankle, II) hip-knee and III) trunk-hip. No differences were found in coordination, but MP runners showed higher hip-knee and trunk-hip CV in downhill sections, …

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The Return To Run Process For Females Following A Tibial Bone Stress Injury: A Scoping Review., Esther George, Kelly Sheerin, Duncan Reid Professor Jul 2023

The Return To Run Process For Females Following A Tibial Bone Stress Injury: A Scoping Review., Esther George, Kelly Sheerin, Duncan Reid Professor

ISBS Proceedings Archive

Tibial bone stress injuries (BSI) are common among female runners and have a high recurrence rate. Complete rehabilitation requires a successful return to running, but there is a lack of guidance for this. This review sought to establish the evidence supporting the return-to-running process following a tibial BSI in females. Sources were identified by searching databases using relevant terms. Study titles and abstracts were screened using inclusion criteria, and 48 articles were selected. An individualised graduated return-to-run programme should be instigated, beginning with walk-run intervals, and progressing running distance ahead of speed. The ‘10% rule’ of graduated loading is not …

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Force Profile Of Functional Leg Muscle Groups In Curve Sprinting - Preliminary Results, Johannes Funken, Marvin Zedler, Svea Lüdorff, Tobias Alt, Kai Heinrich, Wolfgang Potthast Jul 2023

Force Profile Of Functional Leg Muscle Groups In Curve Sprinting - Preliminary Results, Johannes Funken, Marvin Zedler, Svea Lüdorff, Tobias Alt, Kai Heinrich, Wolfgang Potthast

ISBS Proceedings Archive

Research on lower extremity joint and muscle kinetics in athletic curve sprinting is under-represented in the scientific literature. This is an issue due to its importance for training and rehabilitation protocols as well as for injury prevention. In this study, we analysed six male sprinters regarding their force profile of functional lower extremity muscle groups in curve sprinting. Three-dimensional motion capture (Vicon) and four force plates (Kistler) were used to capture kinematic and kinetic data. Inverse dynamic calculations (Anybody), including muscle forces, provide first insights into potential side differences of leg muscle group force profiles between the inside and the …

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Inter-Joint Differences Exist In Kinetic Demand For Performance In High Jump, Toshihide Fujimori, Naoto Tobe, Natsuki Sado Jul 2023

Inter-Joint Differences Exist In Kinetic Demand For Performance In High Jump, Toshihide Fujimori, Naoto Tobe, Natsuki Sado

ISBS Proceedings Archive

We aimed to clarify the lower-limb kinetic determinants of inter-individual variability in flight height in the high jump. We hypothesised that although the take-off of the high jump requires great external power, the proximal (hip) joint is required to function as a stabiliser rather than as a power generator for higher performance. We analysed high jump motions by 16 male high jumpers. For the hip joint, only maximum torque significantly correlated with the flight height. Meanwhile, for the knee joint, both peak positive power and peak torque were correlated with the flight height, with a stronger correlation for power than …

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Head Acceleration Events Using Instrumented Mouthguards In Female Ringette Players, Kenzie B. Friesen, Emily Hemming, Chris Dennison, Reed Ferber, Carolyn Emery Jul 2023

Head Acceleration Events Using Instrumented Mouthguards In Female Ringette Players, Kenzie B. Friesen, Emily Hemming, Chris Dennison, Reed Ferber, Carolyn Emery

ISBS Proceedings Archive

Ringette is a contact sport which prompts high rates of head contacts and concussion, some of the highest reported rates in youth sport. Biomechanical forces at the head can cause concussion injury, therefore examination of head acceleration events and head biomechanics during ringette is useful to understand injury risk and mechanism. The purpose of this study was to describe head acceleration events (HAEs) in female youth ringette players and examine head biomechanics during video-verified head acceleration events. Instrumented mouthguards were worn by 8 players and 36 video-verified HAEs were accumulated from in-game exposure. Results indicate athletes sustain HAEs from both …

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Variability In Overarm Throwing With Resistance In Experienced Handball Players, Andrea B. Fredriksen, Roland Van Den Tillaar Jul 2023

Variability In Overarm Throwing With Resistance In Experienced Handball Players, Andrea B. Fredriksen, Roland Van Den Tillaar

ISBS Proceedings Archive

The purpose of this study was to investigate variability in overarm throwing kinematics with different wearable resistance conditions in handball players as increased variability was expected when testing throwing under new conditions (wearable resistance). Thirteen female handball players performed ten standing throws each under three conditions: normal throws, with light wearable resistance (LW) and heavy wearable resistance (HW), while 3D kinematic data of joint angles and angular velocities were measured with a camera-based motion capture system. The main findings in this study were that variability for all parameters, except a significant lower maximal angular velocity in the high weight condition, …

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Joint Movement Patterns Differ Among Male Recreational Runners With Different Running Style, Pablo Floria, Alberto Sánchez-Sixto, Francisco M. Melgarejo-Meseguer, Jose Luis Rojo, Andrew J. Harrison Jul 2023

Joint Movement Patterns Differ Among Male Recreational Runners With Different Running Style, Pablo Floria, Alberto Sánchez-Sixto, Francisco M. Melgarejo-Meseguer, Jose Luis Rojo, Andrew J. Harrison

ISBS Proceedings Archive

The purpose of this study was to analyse the differences in joint patterns among runners with different spatiotemporal characteristics in the running cycle. Lower extremity kinematic and spatiotemporal parameters were collected for ninety-two recreational runners during a treadmill run at a self-selected speed. A K-means clustering analysis was conducted on normalized stride cadence and Duty Factor to identify running style. The runners were distributed into three clusters with different combinations of spatiotemporal parameters. Only the runners who displayed a high stride cadence and long stance times showed a different movement pattern compared to the rest of the clusters. This study …

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The Effects Of Knee Bracing On Reactive Agility Performance And Emg Activity In Healthy Soccer Players – A Pilot Study, James Fimognari, Derek M. R. Kivi, Carlos Zerpa, Paolo Sanzo Jul 2023

The Effects Of Knee Bracing On Reactive Agility Performance And Emg Activity In Healthy Soccer Players – A Pilot Study, James Fimognari, Derek M. R. Kivi, Carlos Zerpa, Paolo Sanzo

ISBS Proceedings Archive

This pilot study examined differences between braced and non-braced soccer players on measures of reactive agility time and electromyographic (EMG) activity of the gluteus medius (GM), biceps femoris (BF), and vastus lateralis (VL) muscles during the acceleration and change of direction phases of the Y-shaped reactive agility test. Twenty-four participants completed a Y-shaped reactive agility test under two conditions including wearing no knee brace and wearing a Playmaker II knee brace (DonJoy®, Lewisville, Texas) on their dominant leg. Although higher muscle activation was found in the GM and BF muscles during the change of direction phase compared to the acceleration …

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Effects Of Additional Load On Lower Limb Joint Work And The Ratio Between The Braking And Propulsion Countermovement Jump Phase, Isabella Fessl, Christina Groß, Eric Harbour, Jana Holder, Hermann Schwameder Jul 2023

Effects Of Additional Load On Lower Limb Joint Work And The Ratio Between The Braking And Propulsion Countermovement Jump Phase, Isabella Fessl, Christina Groß, Eric Harbour, Jana Holder, Hermann Schwameder

ISBS Proceedings Archive

The purpose of this study was to identify the effect of additional load on lower limb joint work and joint work ratio between the braking and propulsion countermovement jump (CMJ) phase. Thirteen male sport students performed CMJ with five different loads up to 80% of body mass. Total joint work was significantly affected by the additional load and CMJ phase. A significant interaction effect of additional load and CMJ phase was found for ankle and knee joint work. Joint work ratio was significantly affected by load in the knee and hip joint. The braking proportion of the total joint work …

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The Effect Of Lower-Limb Wearable Resistance On Anterior Pelvic Tilt During High-Speed Running: A Pilot Study, Erin Feser Jul 2023

The Effect Of Lower-Limb Wearable Resistance On Anterior Pelvic Tilt During High-Speed Running: A Pilot Study, Erin Feser

ISBS Proceedings Archive

This study determined the effect of two different lower-limb wearable resistance loads on anterior pelvic tilt during high-speed (4.72 – 6.71 m/s) treadmill running. Nine athletes completed a series of 10-second intervals at a self-selected speed for each experimental condition. Compared to unloaded running, the heaviest wearable resistance load (0.91 – 1.24 kg) significantly (p < 0.05) reduced anterior pelvic tilt at the instants of maximal hip extension and maximal hip flexion by -3.54⁰ (ES = 0.80) and -3.30⁰ (ES = 0.55), respectively. Individual responses showed a primary trend towards a reduction in anterior pelvic tilt when running with wearable resistance (6/9 athletes). This study provides initial evidence for the use of lower-limb wearable resistance as a training stimulus to induce pelvic kinematic changes over time.

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Clinical And Biomechanical Comparisons Between Youth Pitchers With And Without A History Of Throwing Arm Pain Or Injur, Shayne D. Fehr, Adam E. Hadro, Brian R. Butler, Janelle A. Cross, Gunnar L. Whealy, Derek S. Damrow, Xue-Cheng Liu Jul 2023

Clinical And Biomechanical Comparisons Between Youth Pitchers With And Without A History Of Throwing Arm Pain Or Injur, Shayne D. Fehr, Adam E. Hadro, Brian R. Butler, Janelle A. Cross, Gunnar L. Whealy, Derek S. Damrow, Xue-Cheng Liu

ISBS Proceedings Archive

This study aimed to determine if there are clinical and kinematic differences in youth pitchers with a self-reported history of throwing arm pain or injury (PI) to those without (NPI). Forty male baseball pitchers ages 9 to 14 years old were divided into a PI group (n=20) and a NPI group (n=20). Injury history, pitching exposure, subject demographics, range of motion, and strength measurements were collected, along with throwing arm kinematics via a motion capture system. When comparing PI and NPI, significant physical differences were observed, with a greater presence of axillary hair, increased forearm length and decreased shoulder internal …

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Effect Of Head Position On Centre Of Mass Variability During Handstand: Preliminary Results, Roman Farana, Pavel Brtva, Gareth Irwin Jul 2023

Effect Of Head Position On Centre Of Mass Variability During Handstand: Preliminary Results, Roman Farana, Pavel Brtva, Gareth Irwin

ISBS Proceedings Archive

The aims of this study were: a) to determine to determine the change in joint angle kinematic variability during the handstand with different head positions, and b) to determine the contributions made by wrist, shoulder, and hip joint angles variability on CoM variability in handstand. Four young active female gymnasts performed 3 trials of handstands with three head positions (normal, straight, and flexed). 3D kinematics were collected for each trial. Statistical differences were analysed using One-way ANOVA and effect sizes (ES) reported. Forward stepwise regression was carried out between CoM variability and joint angle variability. The prevalent control strategies were …

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Comparison Of Kinematics And Emg In The Last Repetition During Different Maximum Repetition Sets In The Bilateral Back Squat, Hallvard Falch Phd, Roland Van Den Tillaar Jul 2023

Comparison Of Kinematics And Emg In The Last Repetition During Different Maximum Repetition Sets In The Bilateral Back Squat, Hallvard Falch Phd, Roland Van Den Tillaar

ISBS Proceedings Archive

This study compared kinematics and electromyography (EMG) in the lower extremities during different phases of the last repetition, when performing the squat of different repetition maximums. Thirteen strength trained men performed a 1-, 3-, 6-, and 10-RM squat, in a randomized order. The main findings were that kinematics was very similar, except for a smaller inclination of the trunk at V0 in the 1-RM compared to other repetitions, and at Vmax1 compared to 10-RM. Furthermore the 1-RM revealed significantly higher EMG amplitude in the vastus lateralis in the sticking- and post-sticking region when compared to 10-RM. It was …

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Comparison Of Markerless And Marker-Based Motion Capture For Estimating External Mechanical Work In Tennis: A Pilot Study, Julie Emmerson, Laurie Needham, Murray Evans, Sean Williams, Steffi Colyer Jul 2023

Comparison Of Markerless And Marker-Based Motion Capture For Estimating External Mechanical Work In Tennis: A Pilot Study, Julie Emmerson, Laurie Needham, Murray Evans, Sean Williams, Steffi Colyer

ISBS Proceedings Archive

This pilot study assessed the accuracy of markerless motion capture to estimate the external mechanical work performed during tennis serves. One tennis player performed 9 serves whilst motion data were captured concurrently with a criterion marker-based and a custom markerless system (utilising HRNet and OpenPose). Centre of mass kinetic and potential energy were calculated and used to compute external mechanical work for all 3 approaches. Markerless methods yielded differences of 2-3% (HRNet) and 6-9% (OpenPose) for external work compared to the criterion measure, with the former regarded as a high level of agreement. Our markerless system, paired with HRNet, shows …

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Peak Vertical Ground Reaction Force Prediction From Kinematics In Male Runners Using Machine Learning Algorithms, Cody Dziuk, Janelle A. Cross Jul 2023

Peak Vertical Ground Reaction Force Prediction From Kinematics In Male Runners Using Machine Learning Algorithms, Cody Dziuk, Janelle A. Cross

ISBS Proceedings Archive

The purpose of this study was to examine if peak vertical ground reaction forces during treadmill running can be predicted from kinematic input using machine learning models. Eighteen healthy male runners' hip, knee, and ankle sagittal angles, with subject metadata, were input into random forest, support vector, and multi-layer perceptron regressors. Thirty strides per side at three speeds were pulled for the dataset. Random forest performed the best with a correlation coefficient of 0.950 and a root mean squared error of 0.456, while multi-layer perceptron was the worst with values of 0.948 and 0.462 respectively. The study showed machine learning …

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Investigating Drill Constraint Kinematics In Male Baseball Pitchers Using Markerless Motion Capture, Tyler J. Dobos, Ryan W. Bench, Lennon Richards, Colin Mckinnon, Mike Holmes, Michael Sonne Jul 2023

Investigating Drill Constraint Kinematics In Male Baseball Pitchers Using Markerless Motion Capture, Tyler J. Dobos, Ryan W. Bench, Lennon Richards, Colin Mckinnon, Mike Holmes, Michael Sonne

ISBS Proceedings Archive

This study investigated the kinematic differences that pitching constraint drills elicit compared to a baseball pitch. 18 male baseball pitchers with average height (183.7 ± 5.2cm), weight (87.4 ± 9.6kg), and skill level (Professional (4), Collegiate (5), High School (9)) were included. Video was recorded using a single camera from the open side. Each pitcher threw 3 maximum effort pitches from a mound. Next, 3 maximum effort throws were recorded for 8 different throwing drills: medicine ball hook’em drill, pivot pickoff drill, foot-up rocker drill, walk-in drill, towel drill, janitor drill, drop-step drill, and long toss. Videos were processed using …

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Mapping Out The Response Sequence Of The Sprint Start, Evan D. Crotty Dr, Laura-Anne M. Furlong Dr, Andrew J. Harrison, Matthieu Milloz Jul 2023

Mapping Out The Response Sequence Of The Sprint Start, Evan D. Crotty Dr, Laura-Anne M. Furlong Dr, Andrew J. Harrison, Matthieu Milloz

ISBS Proceedings Archive

Establishing the limits of sprint start response time (SSRT) requires the mapping of the muscular sequence of activation and mechanical response delays and was the aim of the current study. Sprint start performance of 15 sprinters was examined with kinematic, EMG, and block force data collected. A general muscle activation sequence was identified, with both deltoid muscles, the rear leg rectus femoris, and the rear leg tibialis anterior the first muscles to increase activation from the set position. With ankle dorsiflexion the initial motion during the block push, examining the period between tibialis anterior muscle onset and block force onset …

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Estimation Of Ground Reaction Forces From Markerless Kinematics And Comparison Against Measured Force Plate Data, Steffi Colyer, Laurie Needham, Murray Evans, Logan Wade, Darren Cosker, Dario Cazzola, Polly Mcguigan, James Bilzon Jul 2023

Estimation Of Ground Reaction Forces From Markerless Kinematics And Comparison Against Measured Force Plate Data, Steffi Colyer, Laurie Needham, Murray Evans, Logan Wade, Darren Cosker, Dario Cazzola, Polly Mcguigan, James Bilzon

ISBS Proceedings Archive

This study investigated how accurately ground reaction forces (GRFs) can be estimated from body centre of mass (BCOM) motion derived using markerless motion capture. Fifteen participants performed a countermovement jump (CMJ) on, and a running trial across, force plates. Kinematics captured using markerless and marker-based systems were used to drive IK-constrained OpenSim models. The resulting BCOM displacements were double differentiated to inversely estimate GRFs and compared to force plate data. Markerless-derived estimates were similar to measured GRFs (RMSD = ~70-150 N) and vertical peak force, impulse and rate of force development were also accurately estimated (effect sizes < 0.2), similarly to marker-based outputs. Our markerless workflow shows promise for the estimation of vertical GRF parameters out in the field, without markers or force plates.

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Reliability Of Low-Cost Portable Force Platforms For Measuring Vertical Stiffness During Running, Bryan R. Cobb, Damaris C. Cifuentes Jul 2023

Reliability Of Low-Cost Portable Force Platforms For Measuring Vertical Stiffness During Running, Bryan R. Cobb, Damaris C. Cifuentes

ISBS Proceedings Archive

Ground reaction force (GRF) can provide useful information such as vertical stiffness (Kvert) to practitioners working with runners and sprinters, but high equipment costs are hindering applied research. Low-cost portable force platforms may be a useful alternative to traditional biomechanical equipment. Moderately trained runners (n = 9) completed overground running trials at various speeds (2.15-5.78 m/s), Kvert was determined, and a linear regression was used to characterize the relationship between Kvert and running speed. The results showed moderate to high correlation (r2 = 0.54 to 0.87). At 3.9 m/s (14 km/h), the widest regression …

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Effects Of Calf Anchoring Compression Levels On Ankle Kinematics, Motor Unit Behavior, Energy Cost, And Discomfort During Walking, Jaewoo Cho, Eunsik Choi, Sangheui Cheon, Seongwon Hwang, Jooeun Ahn Jul 2023

Effects Of Calf Anchoring Compression Levels On Ankle Kinematics, Motor Unit Behavior, Energy Cost, And Discomfort During Walking, Jaewoo Cho, Eunsik Choi, Sangheui Cheon, Seongwon Hwang, Jooeun Ahn

ISBS Proceedings Archive

We propose a method for quantifying the anchoring compression of wearable devices using limb occlusion pressure (LOP). Under 0%, 20%, 40%, and 60% of LOP, five healthy male participants performed an isometric ankle plantarflexion task before and after walking on an inclined treadmill. Significant differences were shown in calf discomfort (p < 0.001), and ankle plantarflexion angle (p = 0.013) during walking. Although no significant difference was found for oxygen consumption and motor unit behavior of the gastrocnemius medialis, the maintenance of ankle plantarflexion angle was related to an increase in peak motor unit action potential amplitude and average firing rate at 60% of LOP. The results suggest that subjective assessment is more sensitive than the physiological indices, and calf anchoring force should not exceed 60% LOP to avoid any possible negative effect on the muscle.

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Is Lateral Entry Beneficial To Elite Swimmers? A Preliminary Study, Chen Chen, Jie Gao, Boris Bačić, Shenghao Zhou Jul 2023

Is Lateral Entry Beneficial To Elite Swimmers? A Preliminary Study, Chen Chen, Jie Gao, Boris Bačić, Shenghao Zhou

ISBS Proceedings Archive

The purpose of this study was to improve performance of elite swimmers during the starting phase, by analysing whether the lateral entry technique is beneficial to athletes' starting. Participants’ (N=12) motion data were obtained from a 3D Performance Analysis System (Kistler 9691A1) with three cameras. Extracted 14 parameters were analysed using paired samples t-test. Differences contributing to the lateral entry performance included decrease of both entry angle and maximum depth by 1° and 0.42 m respectively (p<.01), and increase of push force by 0.08 of body weight (p<.01). The preliminary results show that the lateral technique provides a 0.06 s reduction in time to reaching the first 5 m (p<.05) compared to ordinary entry, suggesting performance improvements at start times.

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Estimation Of Ground Reaction Force During Running Using Consumer-Level Wearable Insoles And Machine Learning, Josh Carter, Xi Chen, Dario Cazzola, Grant Trewartha, Ezio Preatoni Jul 2023

Estimation Of Ground Reaction Force During Running Using Consumer-Level Wearable Insoles And Machine Learning, Josh Carter, Xi Chen, Dario Cazzola, Grant Trewartha, Ezio Preatoni

ISBS Proceedings Archive

Data from NURVV Run, a consumer-level wearable technology product, embedding pressure insoles and inertial transducers, were used as an input into a deep learning model for the estimation of vertical ground reaction forces (vGRF) during running. Force data were collected from an instrumented treadmill during a running protocol of mixed gradients and speeds, serving as the gold standard to evaluate the model accuracy. Mean difference in peak vGRF was 0.36 ± 0.26 BW across participants and mean root mean squared error was 0.27 ± 0.15 BW. Model accuracy varied considerably between participants; it would be expected that a larger dataset …

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Gender Differences In Tibial Acceleration In Pre-Season Youth Soccer Players, Taliah Carlson, Jake Melaro, Joshua T. Weinhandl Jul 2023

Gender Differences In Tibial Acceleration In Pre-Season Youth Soccer Players, Taliah Carlson, Jake Melaro, Joshua T. Weinhandl

ISBS Proceedings Archive

In soccer, the players need to be able to change direction quickly, meaning the players need the ability to rapidly accelerate and decelerate. Females at a young age have a higher risk of sustaining injuries that can be caused by rapidly accelerating compared to males. The purpose was to investigate the gender differences in acceleration in youth soccer players. 30 youth soccer players engaged in the following drills: a jog, the M drill, 5-10-5 drill, and a single leg triple jump. This data was collected using inertial measurement units. The peak accelerations in the M drill on the left side …

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