Dynamics of submaximal effort soccer instep kicking

During a soccer match, players are often required to control the ball velocity of a kick. However, little information is available for the fundamental qualities associated with kicking at various effort levels. We aimed to illustrate segmental dynamics of the kicking leg during soccer instep kicking at submaximal efforts. The instep kicking motion of eight experienced university soccer players (height: 172.4 ± 4.6 cm, mass: 63.3 ± 5.2 kg) at 50, 75 and 100% effort levels were recorded by a motion capture system (500 Hz), while resultant ball velocities were monitored using a pair of photocells. Between the three effort levels, kinetic adjustments were clearly identified in both proximal and distal segments with significantly different (large effect sizes) angular impulses due to resultant joint and interaction moments. Also, players tended to hit an off-centre point on the ball using a more medial contact point on the foot and with the foot in a less upright position in lower effort levels. These results suggested that players control their leg swing in a context of a proximal to distal segmental sequential system and add some fine-tuning of the resultant ball velocity by changing the manner of ball impact.     

Segmental dynamics of soccer instep kicking with the preferred and non-preferred leg

Abstract

Detailed time-series of the resultant joint moments and segmental interactions during soccer instep kicking were compared between the preferred and non-preferred kicking leg. The kicking motions of both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The resultant joint moment (muscle moment) and moment due to segmental interactions (interaction moment) were computed using a two-link kinetic chain model composed of the thigh and lower leg (including shank and foot). The mechanical functioning of the muscle and interaction moments during kicking were clearly illustrated. Significantly greater ball velocity (32.1 vs. 27.1 m · s^?1), shank angular velocity (39.4 vs. 31.8 rad · s^?1) and final foot velocity (22.7 vs. 19.6 m · s^?1) were observed for the preferred leg. The preferred leg showed a significantly greater knee muscle moment (129.9 N · m) than the non-preferred leg (93.5 N · m), while no substantial differences were found for the interaction moment between the two legs (79.3 vs. 55.7 N · m). These results indicate that the highly skilled soccer players achieved a well-coordinated inter-segmental motion for both the preferred and non-preferred leg. The faster leg swing observed for the preferred leg was most likely the result of the larger muscle moment.     

Segmental dynamics of soccer instep kicking with the preferred and non-preferred leg

Detailed time-series of the resultant joint moments and segmental interactions during soccer instep kicking were compared between the preferred and non-preferred kicking leg. The kicking motions of both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The resultant joint moment (muscle moment) and moment due to segmental interactions (interaction moment) were computed using a two-link kinetic chain model composed of the thigh and lower leg (including shank and foot). The mechanical functioning of the muscle and interaction moments during kicking were clearly illustrated. Significantly greater ball velocity (32.1 vs. 27.1 m . s(-1)), shank angular velocity (39.4 vs. 31.8 rad . s(-1)) and final foot velocity (22.7 vs. 19.6 m . s(-1)) were observed for the preferred leg. The preferred leg showed a significantly greater knee muscle moment (129.9 N . m) than the non-preferred leg (93.5 N . m), while no substantial differences were found for the interaction moment between the two legs (79.3 vs. 55.7 N . m). These results indicate that the highly skilled soccer players achieved a well-coordinated inter-segmental motion for both the preferred and non-preferred leg. The faster leg swing observed for the preferred leg was most likely the result of the larger muscle moment.     

Impact phase kinematics of instep kicking in soccer

Abstract

The purpose of this study was to capture the lower limb kinematics before during and after ball impact of soccer kicking by examining the influence of both sampling rate and smoothing procedures. Nine male soccer players performed maximal instep kicks and the three-dimensional leg movements were captured at 1000 Hz. Angular and linear velocities and accelerations were determined using four different processing approaches: processed using a modified version of a time-frequency filtering algorithm (WGN), smoothed by a second-order low-pass Butterworth filter at 200 Hz cut-off (BWF), re-sampled at 250 Hz without smoothing (RSR) and re-sampled at 250 Hz but filtered by the same Butterworth filter at 10 Hz cut-off (RSF). The WGN approach appeared to establish representative kinematics, whereas the other procedures failed to remove noisy oscillation from the baseline of signal (BWF), lost the peaks of rapid changes (RSR) or produced totally distorted movement patterns (RSF). The results indicate that the procedures used by some previous studies may have been insufficient to adequately capture the lower limb motion near ball impact. We propose a new time-frequency filtering technique as a better way to smooth data whose frequency content varies dramatically.     

Three-dimensional kinematic correlates of ball velocity during maximal instep soccer kicking in males

Abstract

Achieving a high ball velocity is important during soccer shooting, as it gives the goalkeeper less time to react, thus improving a player's chance of scoring. This study aimed to identify important technical aspects of kicking linked to the generation of ball velocity using regression analyses. Maximal instep kicks were obtained from 22 academy-level soccer players using a 10-camera motion capture system sampling at 500 Hz. Three-dimensional kinematics of the lower extremity segments were obtained. Regression analysis was used to identify the kinematic parameters associated with the development of ball velocity. A single biomechanical parameter; knee extension velocity of the kicking limb at ball contact Adjusted R² = 0.39, p ≤ 0.01 was obtained as a significant predictor of ball-velocity. This study suggests that sagittal plane knee extension velocity is the strongest contributor to ball velocity and potentially overall kicking performance. It is conceivable therefore that players may benefit from exposure to coaching and strength techniques geared towards the improvement of knee extension angular velocity as highlighted in this study.     

Impact phase kinematics of instep kicking in soccer

The purpose of this study was to capture the lower limb kinematics before during and after ball impact of soccer kicking by examining the influence of both sampling rate and smoothing procedures. Nine male soccer players performed maximal instep kicks and the three-dimensional leg movements were captured at 1000 Hz. Angular and linear velocities and accelerations were determined using four different processing approaches: processed using a modified version of a time-frequency filtering algorithm (WGN), smoothed by a second-order low-pass Butterworth filter at 200 Hz cut-off (BWF), re-sampled at 250 Hz without smoothing (RSR) and re-sampled at 250 Hz but filtered by the same Butterworth filter at 10 Hz cut-off (RSF). The WGN approach appeared to establish representative kinematics, whereas the other procedures failed to remove noisy oscillation from the baseline of signal (BWF), lost the peaks of rapid changes (RSR) or produced totally distorted movement patterns (RSF). The results indicate that the procedures used by some previous studies may have been insufficient to adequately capture the lower limb motion near ball impact. We propose a new time-frequency filtering technique as a better way to smooth data whose frequency content varies dramatically.     

Electromyographic analysis of hip adductor muscles in soccer instep and side-foot kicking

ABSTRACT

A possible link between soccer-specific injuries, such as groin pain and the action of hip adductor muscles has been suggested. This study aimed to investigate neuromuscular activation of the adductor magnus (AM) and longus (AL) muscles during instep and side-foot soccer kicks. Eight university soccer players performed the two types of kick at 50%, 75% and 100% of the maximal ball speed. Surface electromyography (EMG) was recorded from the AM, AL, vastus lateralis (VL) and biceps femoris (BF) muscles of both kicking and supporting legs and the kicking motions were three-dimensionally captured. In the kicking leg, an increase in surface EMG with an increase in ball speed during instep kicking was noted in the AM muscle (p < 0.016), but not in AL, VL or BF muscles (p > 0.016). In the supporting leg, surface EMG of both AM and AL muscles was significantly increased with an increase in the ball speed before ball impact during both instep and side-foot kicks (p < 0.016). These results suggest that hip adductor muscles markedly contribute to either the kicking or supporting leg to emphasise the action of soccer kicks.     

Ground reaction forces and kinematics of plant leg position during instep kicking in male and female collegiate soccer players

The players' ability to achieve the greatest distance in kicking is determined by their efficiency in transferring kinetic energy from the body to the ball. The purpose of this study was to compare the kinetics and kinematics of the plant leg position between male and female collegiate soccer players during instep kicking. Twenty-three soccer players (11 males and 12 females) were filmed in both the sagittal and posterior views while performing a maximal instep kick. Plant leg kinetic data were also collected using an AMTI 1000 force platform. There were no significant differences between the sexes in plant leg position, but females had significantly greater trunk lean, plant leg angle, and medial-lateral ground reaction force than the males. Males showed higher vertical ground reaction forces at ball contact, but there were no significant differences in ball speed at take-off between the sexes. Ball speed at take-off was inversely related to peak anterior–posterior ground reaction force ( ? 0.65). The anatomical differences between the sexes were reflected in greater trunk lean and lower leg angle in the females.     

Ground reaction forces and kinematics of plant leg position during instep kicking in male and female collegiate soccer players

The players' ability to achieve the greatest distance in kicking is determined by their efficiency in transferring kinetic energy from the body to the ball. The purpose of this study was to compare the kinetics and kinematics of the plant leg position between male and female collegiate soccer players during instep kicking. Twenty-three soccer players (11 males and 12 females) were filmed in both the sagittal and posterior views while performing a maximal instep kick. Plant leg kinetic data were also collected using an AMTI 1000 force platform. There were no significant differences between the sexes in plant leg position, but females had significantly greater trunk lean, plant leg angle, and medial-lateral ground reaction force than the males. Males showed higher vertical ground reaction forces at ball contact, but there were no significant differences in ball speed at take-off between the sexes. Ball speed at take-off was inversely related to peak anterior-posterior ground reaction force (-0.65). The anatomical differences between the sexes were reflected in greater trunk lean and lower leg angle in the females.     

Three-dimensional kinematic differences between the preferred and non-preferred limbs during maximal instep soccer kicking

Abstract

The current investigation aimed to determine whether there are differences in ball velocity and 3D kinematics when performing maximal kicks with the dominant and non-dominant limbs. Seventeen male academy soccer players performed maximal speed place kicks with their dominant and the non-dominant limbs. The 3D kinematics of the lower extremities were obtained using a 10-camera motion capture system operating at 500 Hz. Hip, knee and ankle joint kinematics were quantified in the sagittal, coronal and transverse planes and then contrasted using paired t-tests. Significantly higher ball velocities were obtained with the dominant limb. Foot linear velocity and knee extension velocity at ball contact were also found to be significantly greater in the dominant limb. That reduced ball velocities were observed between kicking limbs highlights the potential performance detriments that may occur when kicking with the non-dominant limb; thus, it is recommended that additional bilateral training be undertaken in order to attenuate this and improve overall kicking performance.     

Biomechanical differences in soccer kicking with the preferred and the non-preferred leg

The aims of this study were to examine the release speed of the ball in maximal instep kicking with the preferred and the non-preferred leg and to relate ball speed to biomechanical differences observed during the kicking action. Seven skilled soccer players performed maximal speed place kicks with the preferred and the non-preferred leg; their movements were filmed at 400 Hz. The inter-segmental kinematics and kinetics were derived. A coefficient of restitution between the foot and the ball was calculated and rate of force development in the hip flexors and the knee extensors was measured using a Kin-Com dynamometer. Higher ball speeds were achieved with the preferred leg as a result of the higher foot speed and coefficient of restitution at the time of impact compared with the non-preferred leg. These higher foot speeds were caused by a greater amount of work on the shank originating from the angular velocity of the thigh. No differences were found in muscle moments or rate of force development. We conclude that the difference in maximal ball speed between the preferred and the non-preferred leg is caused by a better inter-segmental motion pattern and a transfer of velocity from the foot to the ball when kicking with the preferred leg.     

Biomechanical differences in soccer kicking with the preferred and the non-preferred leg

The aims of this study were to examine the release speed of the ball in maximal instep kicking with the preferred and the non-preferred leg and to relate ball speed to biomechanical differences observed during the kicking action. Seven skilled soccer players performed maximal speed place kicks with the preferred and the nonpreferred leg; their movements were filmed at 400 Hz. The inter-segmental kinematics and kinetics were derived. A coefficient of restitution between the foot and the ball was calculated and rate of force development in the hip flexors and the knee extensors was measured using a Kin-Com dynamometer. Higher ball speeds were achieved with the preferred leg as a result of the higher foot speed and coefficient of restitution at the time of impact compared with the non-preferred leg. These higher foot speeds were caused by a greater amount of work on the shank originating from the angular velocity of the thigh. No differences were found in muscle moments or rate of force development. We conclude that the difference in maximal ball speed between the preferred and the non-preferred leg is caused by a better inter-segmental motion pattern and a transfer of velocity from the foot to the ball when kicking with the preferred leg.     

Comparison of support leg kinetics between side-step and cross-step cutting techniques

The purpose of this study was to investigate differences in the support leg joint moment and moment power between side-step (SS) and cross-step (CS) cutting techniques with a prescribed 90° cutting angle. Ground reaction forces (1,000 Hz) and three-dimensional kinematics (250 Hz) of SS and CS cutting techniques were collected from 20 male college athletes. Normalised peak knee extension moment was larger in the SS technique than in the CS technique (0.40 ± 0.10 in SS; 0.26 ± 0.08 in CS). In the SS technique, the knee extensors ( ? 0.10 ± 0.06 in SS; ? 0.02 ± 0.04 in CS) and ankle plantarflexors ( ? 0.12 ± 0.05 in SS; ? 0.07 ± 0.03 in CS) did significantly more negative work (normalised). The direction change angle (40.5 ± 8.7° in SS; 33.0 ± 6.8° in CS) and the decrease in horizontal velocity of the centre of mass ( ? 0.63 ± 0.23 m/s in SS; ? 0.31 ± 0.23 m/s in CS) were significantly larger in the SS technique. These results suggest that the SS technique is an effective means of changing running direction at the expense of velocity of the centre of mass and that the CS technique is better for minimising the reduction in horizontal velocity of the centre of mass.     

Hip joint kinetics in the table tennis topspin forehand: relationship to racket velocity

The purpose of this study was to determine hip joint kinetics during a table tennis topspin forehand, and to investigate the relationship between the relevant kinematic and kinetic variables and the racket horizontal and vertical velocities at ball impact. Eighteen male advanced table tennis players hit cross-court topspin forehands against backspin balls. The hip joint torque and force components around the pelvis coordinate system were determined using inverse dynamics. Furthermore, the work done on the pelvis by these components was also determined. The peak pelvis axial rotation velocity and the work done by the playing side hip pelvis axial rotation torque were positively related to the racket horizontal velocity at impact. The sum of the work done on the pelvis by the backward tilt torques and the upward joint forces was positively related to the racket vertical velocity at impact. The results suggest that the playing side hip pelvis axial rotation torque exertion is important for acquiring a high racket horizontal velocity at impact. The pelvis backward tilt torques and upward joint forces at both hip joints collectively contribute to the generation of the racket vertical velocity, and the mechanism for acquiring the vertical velocity may vary among players.     

足球运动踢球腿摆动阶段的不同时相运动特征

运用生物力学手段对5名高水平足球运动员摆动腿进行研究发现:根据摆动腿环节摆动顺序与环节摆动速度相结合的方法可将其划分为用力蹬伸、主动后摆、大腿前摆、小腿前摆,脚触球5个阶段.其中,用力蹬伸阶段是不可忽视的重要阶段之一,主动后摆阶段摆动腿应在不影响前摆速度的前提下尽力后摆;大腿前摆阶段摆动腿应在大腿摆到一定幅度时进行积极制动,摆动幅度不宜过大;小腿前摆阶段摆动腿除了膝关节的积极制动外还应主动施力.     

Dynamics of the game in soccer: Detection of T-patterns

Abstract

Traditional approaches to the quantification of team sports have proved to be limited in their ability to identify complex structural regularities that, despite being unobservable, nonetheless underlie the development of the sporting contest between opposing teams. This paper describes a method for detecting the dynamics of play in professional soccer through the analysis of temporal patterns (T-patterns). The observation instrument used was SOF-5, which is especially designed for studying the dynamics of the game in soccer. The recording consisted of within-session monitoring using the MATCH VISION STUDIO 3.0 software, while the THEME software was used to detect and analyse T-patterns. These T-patterns revealed regularities in the playing style of the observed team, FC Barcelona. The structures detected included a ball possession pattern, whereby the ball was first kept in the central zone before being played forward, through several moves, into the zones closest to the opposing team's goal in order to disrupt the latter's equilibrium. The results obtained show that it is possible to identify stable temporal structures that provide information about concurrent interaction contexts with respect to lateral position and zone. As such, the proposed methodology appears to be useful in detecting complex structures within the game of soccer, structures which may help coaches to design attacking and defensive strategies.     

Age and gender differences in kinematics of powerful instep kicks in soccer

Soccer kicking training should be adjusted to the characteristics of the athletes. Therefore, examination of differences in kicking kinematics of females and pubertal players relative to males is worthwhile. The purpose of the study was to compare kicking kinematics and segmental sequence parameters between male, female, and pubertal players. Ten adult male, ten adult female, and ten male pubertal players participated in the study. Participants performed five consecutive kicking trials of a stationary ball, as powerful as they could. Analysis of variance showed significantly higher ball velocity, higher joint linear velocities for the knee and the hip, and higher angular velocities of the knee and the ankle for males compared to female and pubertal players (p < 0.05). Similarly, the peak joint velocity was achieved significantly closer to ball impact in males compared to other groups (p < 0.05). Males also showed a more plantarflexed ankle immediately before ball impact (p < 0.05). Females and pubertal players may benefit from skill training aiming to increase ankle plantarflexion and hip flexion prior to ball impact, and to adjust thigh and shank motion, such that the shank–foot segment travels through a higher range of motion and with a greater velocity.     

Changes in organisation of instep kicking as a function of wearing compression and textured materials

This study investigated effects of wearing compression garments and textured insoles on modes of movement organisation emerging during performance of lower limb interceptive actions in association football. Participants were six skilled (age?=?15.67?±?0.74 years) and six less-skilled (age?=?15.17?±?1.1 years) football players. All participants performed 20 instep kicks with maximum velocity in four randomly organised insoles and socks conditions, (a) Smooth Socks with Smooth Insoles (SSSI); (b) Smooth Socks with Textured Insoles (SSTI); (c) Compression Socks with Smooth Insoles (CSSI); and (d), Compression Socks with Textured Insoles (CSTI). Results showed that, when wearing textured and compression materials (CSSI condition), less-skilled participants displayed significantly greater hip extension and flexion towards the ball contact phase, indicating larger ranges of motion in the kicking limb than in other conditions. Less-skilled participants also demonstrated greater variability in knee–ankle intralimb (angle–angle plots) coordination modes in the CSTI condition. Findings suggested that use of textured and compression materials increased attunement to somatosensory information from lower limb movement, to regulate performance of dynamic interceptive actions like kicking, especially in less-skilled individuals.     

Effect of the racket mass and the rate of strokes on kinematics and kinetics in the table tennis topspin backhand

The purpose of this study was to investigate the effect of the racket mass and the rate of strokes on the kinematics and kinetics of the trunk and the racket arm in the table tennis topspin backhand. Eight male Division I collegiate table tennis players hit topspin backhands against topspin balls projected at 75 balls · min^?1 and 35 balls · min^?1 using three rackets varying in mass of 153.5, 176 and 201.5 g. A motion capture system was used to obtain trunk and racket arm motion data. The joint torques of the racket arm were determined using inverse dynamics. The racket mass did not significantly affect all the trunk and racket arm kinematics and kinetics examined except for the wrist dorsiflexion torque, which was significantly larger for the large mass racket than for the small mass racket. The racket speed at impact was significantly lower for the high ball frequency than for the low ball frequency. This was probably because pelvis and upper trunk axial rotations tended to be more restricted for the high ball frequency. The result highlights one of the advantages of playing close to the table and making the rally speed fast.