Golf is an international sport that has become increasingly more popular in recent times. Previous literature has shown that golf approach shots are crucial to the success of elite golfers. However, there is no known publication investigating distances less than 100 yards, known as the short game. The primary purpose of this study was to collect comprehensive data on 3D biomechanical variables of the short game at four target distances in college-aged, male golfers. Participants were instructed to hit five successful shots at each target distance: 30 yards, 50 yards, 70 yards and full swing (maximal distance) yardage. A motion capture system recorded kinematic and temporal parameters of golfer movement, additional to a golf simulator that collected ball carry distance of each shot. Distance did have a significant ( ≤ 0.05) effect on swing phase timing, angular velocities and motion sequencing. Movement sequencing within the short game displayed irregular patterns across all distances and phases, with a partial proximal-to-distal pattern (pelvis → shoulder girdle → arms → club) at best. The findings of this study show that the short game swing did present its own unique motion patterns that will require practice as its own skill.

Early upper trunk rotation during baseball pitching has been associated with higher upper-limb kinetics. However, its relationship with arm fatigue after repetitive pitching is unclear. This study aimed to investigate associations between upper trunk rotation kinematics and arm fatigue. A total of 14 healthy male pitchers (age 27.1 ± . 9.0 yrs) threw 45 pitches across three innings. Pitching mechanics and ball velocity were assessed using 3-D motion analysis (Vicon, UK) and Rapsodo (Rapsodo, USA). Subjective arm fatigue was assessed by CR-10 Borg scale, whereas grip and shoulder external rotation strength were evaluated before and after pitching sessions. Ball velocity and the timing of upper trunk rotation did not change significantly throughout the three innings. Three-inning pitching produced significant levels of subjective and objective arm fatigue. The onset timing of upper trunk rotation (OTUTR) had significant effects on CR-10 Borg scale and ball velocity. The magnitude of effect of OTUTR on ball velocity may be clinically significant. These findings suggest that the timing of upper trunk rotation may not significantly affect arm fatigue with relatively low pitch counts, and early OTUTR may lead to early reduction in ball velocity.

This study examined the effect of 6-week training to improve horizontal deceleration ability on sprint acceleration and countermovement jump (CMJ) neuromuscular performance (NMP) parameters. Twenty male soccer players were divided into the training (TRA), and the control (CON) group. Pre-and post-training players performed an acceleration-deceleration ability test (ADA) and a jump on a vertical axis dual force plate. ADA deceleration parameters were analysed using Kinovea Software. Distance-to-stop (), time-to-stop (), 20 m sprint time (), CMJ parameters were measured at pre-post-training. The largest improvement was determined in the TRA in the (effect size = 0.88). Despite the increase in the weight of the TRA, was shortened by 5.62% in TRA and 1.91% in CON. Deceleration ability was evaluated with CMJ eccentric parameters. While the percentage change of eccentric peak force differed between the groups, eccentric peak power (11.84 vs. 14.57 W·kg, ds: 0.72) and velocity (0.91 vs. 1.05 m.s, ds: 0.70) increased. Accordingly, it was determined that the improvement in CMJ eccentric and concentric peak velocity was due to speed-based power output. The training improved the maximum horizontal deceleration ability and confirmed that concentric peak velocity, as well as CMJ eccentric parameters, is an important NMP determinant of horizontal deceleration ability.

This study aimed to investigate the effect of the flutter kick on the propulsive force generated by a stroke. Eight male swimmers performed 20 m front crawl trials under two conditions: the Whole Condition, involving maximum effort (T100%) and stroke frequencies at 70, 80, and 90% of T100%, and the Arm Condition, which excluded the flutter kick and matched stroke frequencies with the Whole Condition. Various parameters, including swimming velocity, stroke frequency, stroke length, three-dimensional (3D) resultant hand speed, and hand propulsion were calculated based on underwater 3D motion analysis and hand pressure distribution measurements. A two-way repeated-measures ANOVA was conducted to assess differences, considering the conditions and instructed frequencies as the two factors. There was no significant interaction between the condition and intensity for any of the variables. There was a significant main effect of condition on swimming velocity and stroke length, with these variables being 16.9-18.5% higher and 17.3-19.5% longer, respectively, in the Whole Condition compared to the Arm Condition. However, there was no difference in hand propulsion between the conditions, and it was clarified that the flutter kick did not affect hand propulsion at any swimming velocity.

This study aimed to synthesise the body of knowledge on kinematics, active drag and energetics determinants of energy cost variability in the breaststroke technique. Methodological procedures considering the standards for systematic reviews according to the '"Preferred Reporting Items for Systematic Reviews and Meta-Analyses"' were employed. Searches were conducted in four prominent databases. A total of 1,464 articles were identified, of which 201 met the eligibility criteria. After evaluation, 73 articles were included for synthesis in this review. The included studies had a mean score (± SD) of 9.14 ± 1.76 points regarding the quality assessment. The present review identified three distinct domains of variables: kinematics (including stroke kinematics and coordination parameters), active drag, and energetics. The findings underscored the pivotal role of stroke kinematics, including stroke rate, stroke length, stroke index, and intra-cyclic variations of velocity, in influencing energy cost during breaststroke swimming. Additionally, the analysis highlighted the significance of propulsive and non-propulsive phases, arm-to-leg timing, and buoyancy in breaststroke technique. Notably, breaststroke exhibited higher values of active drag, frontal area, and energy cost, while maintaining lower velocity compared to other swimming techniques. Overall, this synthesis of literature highlights the holistic nature of energy cost in breaststroke swimming.

This study examined the acute effects of different loading protocols on 180° change of direction (COD) performance in eleven male handball players. Participants performed a 10-0-5 COD test under seven conditions: without an external load, and with 3, 6, and 9 kg loads applied under two modes-assisted into the COD and resisted out of it and resisted into the COD and assisted out of it. While total COD time was not affected ( = 0.098; η = 0.16), significant phase effects were observed ( < 0.001; η ≥ 0.55). Loading protocols significantly influenced velocity, acceleration, and their distances from COD ( < 0.001; η ≥ 0.37). Significant phase effects were observed for all step kinematic variables ( ≤ 0.037; η ≥ 0.67), except contact time, and significant interaction (phase*condition) effects for all variables ( ≤ 0.004; η ≥ 0.08), except for step frequency. Assisted-resisted protocols increased deceleration demands through higher COD entry velocities, displaying fewer but longer steps in the acceleration phase and greater steps taken during the deceleration phase. Resisted-assisted protocols decreased deceleration demands due to lower COD entry velocities, displaying shorter, but more steps taken in the acceleration phase, and fewer steps taken in the deceleration phase. These findings suggest that assisted-resisted and resisted-assisted loading protocols can be used to selectively overload specific phases of COD performance.

High jump is a power-demanding motor task. Jumpers extend the take-off leg joints with maximum effort, but kinetic requirements (i.e. torque/power) for each joint are unclear. Here we show the inter-joint differences in the kinetic exertion related to the flight height in high jump trials by 16 male high jumpers (personal best record: 1.90-2.35 m). For the knee joint, both maximum net power and maximum norm of torque were significantly and positively correlated with flight height, with a stronger correlation for maximum net power ( = 0.70) than for maximum norm of torque ( = 0.52). For the hip joint, maximum norm of torque was significantly correlated with flight height ( = 0.62), but maximum net power ( = 0.36) was not. Both torque and power exhibited the proximal-to-distal sequence (from hip to ankle). The norm of ground reaction force peaked almost simultaneously with the hip torque while external net power peaked with knee power. We suggest that the required musculoskeletal function of each joint differs even in the same task. We suggest that it may be effective to adapt the different training programme between joints to improve performance. Jumpers should prioritise torque exertion for the hip and power exertion for the knee.

The study aimed to clarify the difference in the support leg dynamics and its mechanical role in producing the interaction torque acting on the kicking leg knee between female and male soccer players. Three-dimensional motion (500 Hz) and the ground reaction force (1000 Hz) were captured during the instep kicking of twenty female and twenty male players. Powers due to the support leg knee joint torque and the interaction torque were computed. A significantly smaller positive power of the interaction torque due to the support leg action seen in female players concurred with a significantly smaller positive knee joint power in the support leg. In contrast, female players exhibited a comparable positive power of the interaction torque due to the kicking leg action. Female players had a unique, more inclined lower leg posture of the kicking leg to compensate for their lesser power of the interaction torque due to the support leg action, thereby achieving a comparable magnitude of the power of the total interaction torque. Based on the dynamic background, they maintain a comparable lower leg angular velocity to that of male players immediately before ball impact.

This study aimed to clarify the disparities in trunk rotation and attack arm movement and their effect on hand kinematics adjustments between straight-line (SL) and diagonal-line (DL) volleyball jump serves. Thirteen male professional volleyball players (age 21.53 ± 5.39 years, height 1.95 ± 0.06 m, body mass 86.48 ± 11.63 kg, experience 8.61 ± 3.47 years) performed SL and DL jump serve, with three-dimensional coordinate data captured using a motion capture system (200 hz). Paired t-test and statistical parametric mapping examined kinematic differences between the two serving directions. At ball contact (BC), the speed of the attack arm hand was significantly faster in DL (16.99 ± 1.36 m/s) compared to SL (16.37 ± 1.53 m/s), whereas the face angle was significantly smaller in DL (1.98 ± 11.75°) than in SL (17.60 ± 17.98°). Forward rotation angles of the pelvic and upper torso at BC were significantly greater in DL (28.47 ± 10.89°; 21.30 ± 10.25°) than in SL (18.27 ± 12.46°; 9.09 ± 14.41°). During the arm swing phase, the pelvic's forward rotation angles in DL were significantly greater than in SL at 42-72% spiking motion, and the upper torso's angles were significantly greater at 49-58% spiking motion. These findings underscore the importance of adjusting pelvic and upper torso rotations to control the hand's face angle when serving in the diagonal line.

We investigated spatiotemporal kinematics during top speed sprinting and biomechanical running strategies in 98 male intercollegiate athletes from a range of athletic backgrounds in track and field (TF,  = 28) and team sports (TS,  = 70). Participants completed 40 m running trials with sagittal plane motion analyses of high-speed video captured from 30 m to 40 m. Across the entire sample, measures of contact time, step rate, step length, flight length and duty factor (ratio of contact duration to stride duration) were meaningfully correlated with top speed ( < 0.05, 0.51 ≤ | or ρ| ≤ 0.78). Flight time and contact length were weakly correlated with top speed ( < 0.05, 0.27 ≤ | or ρ| ≤ 0.34). When comparing sub-groups of Slow TF ( = 14) and Fast TS athletes ( = 22) with similar top speeds (~9.3 m/s), Fast TS athletes clearly demonstrated a more ground-based strategy, with longer ground contact times and contact lengths, shorter flight times and flight lengths, and larger duty factors. Therefore, the results of this study suggest that existing technical models and normative metrics based on data from TF athletes could require modification when evaluating and coaching sprinting performance with TS athletes.

Wrist and hand biomechanics under full-body load are not fully understood. To identify potential anatomy-related differences in hand loading, 15 former collegiate athletes completed a 45-second handstand on a novel emed® pressure platform system. Center of pressure (CoP) and force distribution across the palmar surface were analysed during the stabilised phase. Maximum force, mean pressure, and contact area were calculated in four palmar anatomic subregions: hypothenar, thenar, metacarpals, and fingers. These values were related to ulnar variance measurements obtained from a participant handstand hold in a weight-bearing computed tomography machine. About 93% of participants shifted their CoP towards their dominant hand (  <  0.001), and among all participants, the dominant hand applied an average of 8.91% (  =  0.002) higher maximum force than the nondominant hand. The proportion of total mean force was highest in the hypothenar (47.1%) and thenar regions (36.5%). Every 1.00 mm increase in ulnar variance corresponded to a 2.8% increase in maximum force in the hypothenar region ( = 0.037). This investigation emphasises the role of gymnastics hand dominance on left/right hand weight distribution and the importance of the hypothenar zone in distributing pressure during handstands. It also indicates that force transmission through the wrist to the palm is contingent on radioulnar positioning.

In cricket fast bowling, late swing can increase interception difficulty for opposition batters. However, little is known about the occurrence and cause of late swing. This study investigated ball kinematics and the effect of changing kinematics on late swing with new cricket balls. Markers were placed on the ball to track the trajectory and calculate kinematics u1sing a motion analysis system. Fast bowlers generated varying ball kinematics (linear velocity, angular velocity and seam orientation) and delivery trajectories. A random intercept linear mixed-effects model identified that decreasing ball velocity (release velocity: effect = 0.21,  = 0.051, and pitch velocity: effect = -0.27,  = 0.011) and increasing seam stability (release stability: effect = -0.02,  < 0.001 and pitch stability: effect = 0.02,  = 0.001) were associated with greater late swing. To achieve these changes and create late swing, bowlers can pitch the ball on a full length and impart a large amount of backspin on the ball. However, swing can be influenced by factors such as wind and ball composition and late swing may be difficult to control. Bowlers and coaches should develop strategies to generate late swing but recognise it may be unpredictable in some situations.

Peak tibial accelerations are used to monitor impact severity during distance running and as input for bio-feedback. Here, peak tibial accelerations were compared between rearfoot and forefoot strikes. Two different studies were undertaken by independent research centres. Tibial acceleration and optical motion capture were collected in 14 rearfoot strikers who changed to a forefoot strike in the first centre. In the second centre, tibial acceleration of 14 other rearfoot strikers and nine forefoot strikers were collected and processed. In over-ground level running at a submaximal speed, the resultant peak tibial acceleration was greater in the instructed forefoot strike condition (Δ = 7.6 ± 1.3 g, mean ± standard error difference) and in the habitual forefoot strikers (Δ = 3.7 ± 1.1 g) than in the rearfoot strikers. The shank kinematics revealed a greater decrease in antero-posterior velocity following touchdown in the forefoot strike condition. The forefoot strikes experienced greater posterior tibial acceleration, which resulted in an increased resultant peak tibial acceleration that also occurred earlier than in the rearfoot strikes. No significant difference in axial peak tibial acceleration was found between these foot strike patterns. In conclusion, the foot strike pattern differently affects peak tibial accelerations in level running, which can have implications for monitoring and biofeedback applications.

This study aimed to determine kinematic and kinetic key performance indicators (KPI) of swimming turn performance using principal component analysis (PCA) and multiple linear regression analysis and provide reference values using percentiles. Touch and tumble turn performances of male ( = 68) and female ( = 48) Swiss national team members from three age categories-adult (20.2 ± 2.7 yrs, 790 ± 57 points), junior (16.2 ± 0.8 yrs, 729 ± 53 points) and youth swimmers (14.4 ± 1.0 years of age, 667 ± 53 World Aquatics swimming points, respectively)-were assessed with a motion analysis system equipped with a force plate on the pool wall, one over- and four underwater cameras sampling forces at 500 Hz and footages at 100 Hz. The PCA reduced the 27 original variables by up to 15% depending on turn type and age category using Varimax component loading of >0.6 and explained up to 91% of the total variance. The highest Varimax component loadings for each principal component were used to determine KPI for each turn type and age category using multiple-regression analysis with total turn time as dependent variable. These KPI should be used to interpret turn performances and identify individual swimmers' strengths, weaknesses and future potentials with the help of the percentiles as reference values.

Strength programmes have shown good results in preventing swimmer's shoulder. However, there aren't studies based on electromyographic (EMG) analysis in these programmes. This study aims to compare an EMG activity of the middle trapezius (MT), lower trapezius (LT), infraspinatus (IS), serratus anterior (SA), and pectoralis major (PM) in two swimmer's shoulder preventive programmes - one performed with elastic band and the other with weights. Twenty competitive swimmers performed two strength programmes consisting of five exercises each, while the analysis of EMG activity in MT, LT, IS, SA, and PM for each exercise was recorded. The superficial EMG was used to collect data at a sampling frequency of 1000 hz. The Paired Sample T-test or the Wilcoxon test was applied to compare EMG activity between programmes. The internal rotation at 90º ( < 0.001) and external rotation at 90º ( ≤ 0.01) exercises produced high myoelectric shoulder muscle activity with an elastic band. Conversely, scapular punches ( < 0.001) exercise has high shoulder EMG activity when performed with weights. Performing the same preventive exercise programme with two different instruments produces great variability in the myoelectric activity of the shoulder muscles.

This study aims to investigate the influence of a new semi-rigid knee joint braces on kinematics using the Opti-knee knee joint kinematic analysis system at various exercise speeds. Twenty-four healthy young male adults were recruited for this study. Participants were randomly assessed while wearing and not wearing knee brace at four different speeds on a treadmill: normal walking (3.6 km/h), brisk walking (5.4 km/h), jogging (9 km/h), and moderate intensity running (10.8 km/h). Six degrees of freedom kinematic data from the knee joint were collected. Paired t-tests were conducted to calculate the kinematic differences. At speeds of 3.6 km/h and 5.4 km/h, wearing the knee brace led to reduced knee joint mobility in anterior-posterior translation, superior-inferior translation, internal-external rotation, and flexion-extension angles during the stance phase ( < 0.05). At 9 km/h, wearing the brace reduced knee joint internal-external rotation and flexion-extension mobility during the stance phase ( < 0.05). At 10.8 km/h, wearing the brace reduced knee joint flexion-extension mobility during the stance phase ( < 0.05). Wearing brace has significant influence on knee kinematics at four speeds, and the effect of brace varies with the speed of movement.

Functional data analysis (FDA) is a contemporary area of statistics designed for analysis of functions or curves. FDA has grown in human movement applications over the last three decades, with it being applied across a range of sport applications including rowing, weightlifting, diving, race-walking, jumping and running. Functional principal components analysis (PCA) has been the most commonly used technique in sports biomechanics, often being applied to better understand characteristics of variability present in curves from biomechanical variables sampled from sporting movements. Given that FDA is an area of statistics with specific techniques for processing and analysing data, it provides one valuable platform for biomechanists to understand and think about their data more holistically. Further, the visual interpretability that FDA techniques provide, there is great potential for FDA to be used beyond research contexts, as a suite of practical tools to assist practical sports biomechanists in making decisions in sport. This review aims to demonstrate some methods yet to be applied in sports biomechanics, with simple sports biomechanics data applications taken from rowing. This article aims to showcase the value that FDA may have in assisting practitioners as they make decisions with athletes regarding their movement characteristics.

Stiffness (k) describes a material's resistance to deformation and is useful for understanding neuromuscular function, performance, and injury risk. The aim of this study is to compare the lower limb stiffness method (), which uses only force plate data, with methods combining force plate and motion capture data to calculate stiffness during the eccentric phase of a countermovement.

Historically, the wind-up delivery is considered a more biomechanically advantageous pitching motion compared to the stretch. Recently, some pitchers have shifted to pitching exclusively from the stretch regardless of the game situation. The goal of this study was to compare temporal, kinematic and kinetic variables between the wind-up and stretch deliveries. Professional pitchers ( = 52, 189.1 ± 4.8 cm, 92.8 ± 8.4 kg) threw fastballs evaluated by 3D-motion capture (480 Hz) from both the wind-up and stretch deliveries. Within a pitcher, there was no significant difference in ball velocity between the two deliveries ( = 0.15). The stretch delivery was significantly quicker to ball release at toe off 2 ( < 0.001) (the last frame the pitcher's foot contacts the ground before progressing to maximum knee height) and maximum knee height ( < 0.001). The majority of differences occurred prior to foot contact. The wind-up delivery produced greater maximum shoulder external rotation ( < 0.001) and lead knee flexion at ball release ( < 0.001). Pitching from the stretch incurred greater shoulder superior force ( < 0.001). It remains unknown if this is clinically significant as pooled means show only a 2% difference. Therefore, pitching a fastball from either the wind-up or stretch delivery provides comparable mechanics and throwing arm load with likely comparable risk of injury.

This study aims to objectively evaluate the trunk posture of sweep rowers (bow-side rowers/stroke-side rowers) and compare the results with scull rowers and non-rowing controls. Sixty-four healthy individuals divided into four groups were assessed using a DIERS formetric III 4D device that is based on a method of moiré topography. There were seven parameters observed in an assessment of standing posture, and eight parameters were studied for an evaluation of posture during the gait cycle. In comparison with non-rowing controls and scull rowers, stroke-side rowers showed significantly greater rotational deviation of the trunk at the L3 vertebra level and a greater magnitude of scoliosis angle during walking throughout the single support phase on the left leg ( < 0.05). Stroke-side rowers also demonstrated greater magnitude of scoliosis angle than non-rowing controls in double support phase in the transition from the left to the right leg ( < 0.05). Moreover, as opposed to non-rowing controls, stroke-side rowers and scull rowers showed significantly greater values of coronal imbalance ( < 0.05). Bow-side rowers differed from non-rowing controls and scull rowers in a significantly greater magnitude of scoliosis angle throughout the single support phase on the left leg ( < 0.05). Trial registration number: clinicaltrials.gov (identifier: NCT05685563).

In snowboard freestyle disciplines, the amount of rotation is commonly determined as the sum of rotations around all board axes and is the most important indicator of the trick difficulty across all snowboard freestyle disciplines. Based on the type of rotation, tricks can be classified as flatspins, corks and flips. It is not yet known whether the type of rotation of a trick can influence the actual amount of rotation. Therefore, the aim of this study was to determine the amount of deviation, defined as difference between measured and assumed amount of rotation as a function of trick classification, using kinematic motion analysis. The amount of deviation was positive for flatspins (median: 21°; min: -4°; max: 49°) and negative for corks (median: -25°; min: -89°; max: 12°) and flips (median: -28°; min: -94°; max: 13°). Our results demonstrate that there are ways of execution where riders perform corks and flips with a shortcut and flatspins with a detour. This should be taken into account by judges, coaches and riders. Further research is needed to investigate how the shortcut can be influenced.