Impact attenuation provided by shin guards for field hockey
AbstractLow-energy impact testing of hockey shin guards was carried out using a drop test impact rig and a new physical setup protocol. Two brands of shin guards were impacted once (2.6 J, 3.3 J; without and with a sock), and impacted three times (3.3 J; with a sock). The peak force and impulse of a single impact increased with increasing impact energy (by approximately 30 and 7%, respectively) whilst repeated impacts increased the peak force and decreased the impulse (by appro ximately 70 and 3–9%, respectively, between one and three impact events). The presence of a sock attenuated impact force to a greater extent ...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Optimal pacing in road cycling using a nonlinear power constraint
AbstractIn the individual road cycling discipline known as a time-trial, variable power pacing under variable grade conditions leads to improved performance. However, it is unclear whether these power variations result in an optimal finishing time. Typical pacing strategies use an average power constraint, which requires maintaining a constant speed regardless of grade fluctuations; however, this is physiologically infeasible for cyclists. We used an exponentially weighted average (EWA) power constraint in which a nonlinear relationship between the power output and physiological cost was assumed. We defined the optimal pac...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Effect of surrogate design on the measured stiffness of snowboarding wrist protectors
This study investigated how surrogate arm design affected the stiffness of wrist protectors during quasi-static mechanical testing. Three surrogate arms with increasing design complexity were used to test three wrist protectors. The results show that surrogate design does influence the stiffness of snowboarding wrist protectors. Given that the surrogate does influence protector performance, it is recommended that a standard surrogate design is established for research and product testing. (Source: Sports Engineering)
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Evaluation of wireless bat swing speed sensors
AbstractBatter swing speed is an important parameter in understanding the performance of baseball and softball players. A number of swing speed sensors have recently been introduced and are commercially available. The aim of this study was to compare three wireless swing sensors with high speed video. Swing speed from high speed video was measured by differentiating the position coordinates of tracking markers on the bat barrel. On average, the wireless bat swing sensors reported speeds 8% slower than that found from video tracking. The agreement was better at low swing speeds, suggesting that the current generation of wir...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Analysis of speed accuracy using video analysis software
AbstractDetermining an athlete ’s speed from broadcast video is a common practice in sport. Many software packages that perform data extraction from video files are expensive; however, open source software is also available, but lacks published validation for speed measurements. The purpose of this research was to examine the e rror of speed measurements extracted from video during an ice hockey skating exercise using open source software. The subject completed four exercises, at two speeds recorded by broadcast cameras set at five angles. The speeds from the broadcast cameras were compared to speeds calculated from a hi...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Pose tracking with rate gyroscopes in alpine skiing
AbstractThe motion capture of alpine skiing is technically challenging. Motion capture systems using inertial sensors such as gyroscopes and accelerometers have begun to be used in sport. The capture volume of the system can be large enough to cover the whole area of a particular sporting event, because sensors are affixed to the human body itself. The current study developed a method of tracking the pose of an alpine skier using gyroscopes for 3 min with a tracking error of 2° (RMSE). The technical significance of the presented method, which uses one common simple algorithm to improve measurement of pose, applies to ma...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Optimization-based motor control of a Paralympic wheelchair athlete
AbstractThe following research approximated how the central nervous system of Paralympic wheelchair athletes resolve kinematic redundancies during upper-limb movements. A multibody biomechanical model of a tetraplegic Paralympic athlete was developed using subject-specific body segment parameters. The angular joint kinematics throughout a specified Paralympic sport movement (i.e., wheelchair cur ling) were experimentally measured using inertial measurement units. The motor control system of the Paralympian was mathematically modelled and simulated using forward dynamics optimization. The predicted kinematics from differe...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Differences in soccer kicking type identified using principal component analysis
AbstractSoccer kicks are characterized by segmental and joint rotations in multiple planes, where large discrepancies between two- and three-dimensional analyses for angular measurements of soccer kicks exist. The aim of this study was to clarify the differences in motions of the lower limbs and the pelvis required to achieve a shot without rotations as compared with an instep kick. Kinematic parameters obtained from non-rotational shots and instep kicks were analyzed using principal component analysis (PCA). The results clearly demonstrated that the PCA identified the differences in the instep kick and the non-rotational ...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Hydrodynamic characteristics of sea kayak traditional paddles
We present a study of the hydrodynamic characteristics of sea kayak paddles without taking into account the kayaker. We focus on traditional paddles used in the Arctic, one from Greenland and one from the Aleutian Islands. A basic modern European paddle is included in the study for comparison. First the paddle stroke parameters specific to sea kayaking are identified because previous studies were devoted to a competition context. The hydrodynamic force generated by the blade motion is detailed: two terms are identified, one involving the inertia of the water surrounding the blade at the beginning of its motion, and the sec...
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
Correction to: Effect of surrogate design on the measured stiffness of snowboarding wrist protectors
Text referencing these three percentages in the discussion and results is published incorrectly (5 instances). The correct table and text is given below. (Source: Sports Engineering)
Source: Sports Engineering - September 1, 2018 Category: Sports Medicine Source Type: research
A mathematical model for simulating cycling: applied to track cycling
AbstractA review of existing mathematical models for velodrome cycling suggests that cyclists and cycling coaches could benefit from an improved simulation tool. A continuous mathematical model for cycling has been developed that includes calculated slip and steering angles and, therefore, allows for resulting variation in rolling resistance. The model focuses on aspects that are particular, but not unique, to velodrome cycling but could be used for any cycling event. Validation of the model is provided by power meter, wheel speed and timing data obtained from two different studies and eight different athletes. The model i...
Source: Sports Engineering - August 31, 2018 Category: Sports Medicine Source Type: research
The effect of football boot upper padding on dribbling and passing performance using a test –retest validated protocol
This study aimed to assess the effect of upper padding on dribbling and passing performance using a test –retest reliable test setup. Eight university players performed a protocol of dribbling, short and long passing in football boots with 0 and 6 mm of upper padding (Poron foam). The protocol was completed twice; the 0-mm padding results were used for test–retest validation, while the 0-mm versus 6-mm padding results were used to investigate the effect of padding. Dribbling performance was assessed though completion time, number of touches applied and lateral deviation from cones and passing performance through ball ...
Source: Sports Engineering - August 31, 2018 Category: Sports Medicine Source Type: research
A mathematical model for simulating cycling: applied to track cycling
AbstractA review of existing mathematical models for velodrome cycling suggests that cyclists and cycling coaches could benefit from an improved simulation tool. A continuous mathematical model for cycling has been developed that includes calculated slip and steering angles and, therefore, allows for resulting variation in rolling resistance. The model focuses on aspects that are particular, but not unique, to velodrome cycling but could be used for any cycling event. Validation of the model is provided by power meter, wheel speed and timing data obtained from two different studies and eight different athletes. The model i...
Source: Sports Engineering - August 31, 2018 Category: Sports Medicine Source Type: research
The effect of football boot upper padding on dribbling and passing performance using a test –retest validated protocol
This study aimed to assess the effect of upper padding on dribbling and passing performance using a test –retest reliable test setup. Eight university players performed a protocol of dribbling, short and long passing in football boots with 0 and 6 mm of upper padding (Poron foam). The protocol was completed twice; the 0-mm padding results were used for test–retest validation, while the 0-mm versus 6-mm padding results were used to investigate the effect of padding. Dribbling performance was assessed though completion time, number of touches applied and lateral deviation from cones and passing performance through ball ...
Source: Sports Engineering - August 31, 2018 Category: Sports Medicine Source Type: research
Comparative analysis of Hybrid III neckform and an unbiased neckform
AbstractHelmet design and development are an important tool to help mitigate the severity and frequency of head and brain injury in sport and everyday life. Helmet assessment protocols and standards often use the Hybrid III neckform as part of the impacting equipment even though it has a biased response that can affect the results. This research presents an unbiased neckform that can be used for the purposes of head impact testing that does not provide a mechanical directional bias to the impact result. A Hybrid III headform was impacted under a sporting impact protocol with a Hybrid III and an unbiased neckform. The resul...
Source: Sports Engineering - August 29, 2018 Category: Sports Medicine Source Type: research
