Simon B Choppin

• MEng, PhD
• Research Associate at Sheffield Hallam University

Background Obesity and overweight are commonplace, yet attrition rates in weight management clinics are high. Traditional methods of body measurement may be a deterrent due to invasive and time-consuming measurements and negative experiences of how data are presented back to individuals. Emerging new technologies, such as three-dimensional (3D) sur...

Notational analysis investigations of several sports have suggested that the performance characteristics associated with success differ by match closeness. It is not known whether this is the case in tennis. Therefore, this study aimed to first develop operational definitions for closely contested and one‐sided tennis matches, then establish whethe...

Objective The objectives of this study were to: (i) review and provide a narrative synthesis of three-dimensional (3D) foot surface scanning methodological and statistical analysis protocols, and (ii) develop a set of recommendations for standardising the reporting of 3D foot scanning approaches. Methods A systematic search of the SCOPUS, ProQuest...

Introduction: Compare the importance of complex (areas and volumes) and simple (lengths and girths) surface anthropometrics in the descriptive anthropometric assessment of the lower body of male cyclists from different disciplines. Method: Using a 3dMDBody5 3D surface imaging system and bespoke software (KinAnthroScan), anthropometrics of the lower...

The visco-elastic properties of a football influence how it bounces and therefore its performance in a game. Previously, high-speed camera footage has been used to quantify deformation, coefficient of restitution and contact time for an impact between a football and a rigid surface but these systems do not provide any information on the forces acti...

Recent literature has suggested 3D surface imaging to be a potential method of estimating body composition. The aim of this study was to provide an overview of commercially available 3D surface imaging systems that provide body composition estimates. User and system details of complete commercially available whole body 3D surface imaging systems, w...

Background: As obesity increases throughout the developed world, concern for the health of the population rises. Obesity increases the risk of metabolic syndrome, a cluster of conditions associated with type-2 diabetes. Correctly identifying individuals at risk from metabolic syndrome is vital to ensure interventions and treatments can be prescrib...

Traditional body measurement techniques are commonly used to assess physical health; however, these approaches do not fully represent the complex shape of the human body. Three-dimensional (3D) imaging systems capture rich point cloud data that provides a representation of the surface of 3D objects and have been shown to be a potential anthropometr...

Somatotype is an approach to quantify body physique (shape and body composition). Somatotyping by manual measurement (the anthropometric method) or visual rating (the photoscopic method) needs technical expertise to minimize intra- and inter-observer errors. This study aims to develop machine learning models which enable automatic estimation of Hea...

Research has shown that short points (points of 0–4 shots) are crucial in determining the outcome of elite men’s and women’s grass court tennis matches. However, research has not explored the importance of short points in more detail to inform practice design. This study aimed to establish the prevalence and importance of individual rally lengths w...

The accuracy and accessibility of methods to calculate body segment inertial parameters are a key concern for many researchers. It has recently been demonstrated that the magnitude and orientation of principal moments of inertia are crucial for accurate dynamic models. This is important to consider given that the orientation of principal axes is fi...

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Traditional manual anthropometrics have been used extensively in practice to derive indicators of health risk, such as growth disorders or obesity; however, these approaches typically reduce the complex shape of human bodies to a series of simple size measures. Three-dimensional (3D) imaging systems capture detailed and accurate images of human mor...

Manual anthropometrics are used extensively in medical practice and epidemiological studies to assess an individual's health. However, traditional techniques reduce the complicated shape of human bodies to a series of simple size measurements and derived health indices, such as the body mass index (BMI), the waist-hip-ratio (WHR) and waist-by-heigh...

The performance characteristics of elite tennis match-play differ depending on court surface. However, the performance characteristics (e.g. aces, first serve points won, forced errors) most associated with success on different surfaces are currently unknown. With three weeks typically separating Roland Garros and Wimbledon, the transition from cla...

The tennis racket has developed since the origins of Lawn Tennis in the 1870s. This study investigated how the tennis racket developed from 1874 to 2017, using measurements and material classifications for 525 samples. Racket measurements covered geometric, inertial and dynamic properties, and the number of strings. Rackets predating 1970 were main...

KinectFusion is a typical three-dimensional reconstruction technique which enables generation of individual three-dimensional human models from consumer depth cameras for understanding body shapes. The aim of this study was to compare three-dimensional reconstruction results obtained using KinectFusion from data collected with two different types o...

Tennis racket properties are of interest to sports engineers and designers as it allows them to evaluate performance, review trends and compare designs. This study explored mathematical models that correlated to the mass moments of inertia of a tennis racket, both about an axis through the butt and about the longitudinal axis, using its dimensions,...

Performance analysis and identifying performance characteristics associated with success are of great importance to players and coaches in any sport. However, while large amounts of data are available within elite tennis, very few players employ an analyst or attempt to exploit the data to enhance their performance; this is partly attributable to t...

Tennis rackets have advanced significantly since the invention of the game in 1874, including innovations in both shape and materials. Advances in these design parameters have implications for racket performance, especially swing speed. This study tested one hundred rackets, spanning brands and eras, using simple, portable instruments in order to p...

The Hawk-Eye electronic line-calling system gives players the ability to challenge line-calling decisions. It also creates large datasets of ball and player movements during competitive play. In this paper we used a dataset taken from 5 years of the Davis and Fed Cup tournaments (comprising 71,019 points in total) to examine the effect of ball wear...

Stereo camera systems have been used to track markers attached to a racket, allowing its position to be obtained in three-dimensional (3D) space. Typically, markers are manually selected on the image plane, but this can be time-consuming. A markerless system based on one stationary camera estimating 3D racket position data is desirable for research...

Trajectory analysis is an alternative to using wind tunnels to measure a soccer ball's aerodynamic properties. It has advantages over wind tunnel testing such as being more representative of game play. However, previous work has not presented a method that produces complete, speed-dependent drag and lift coefficients. Four high-speed cameras in ste...

In team invasion sports, tactical behaviour can be examined using spatio-temporal data, i.e. the position of the players at a given time. A review of the spatio-temporal metrics used in team invasion sports performance analysis indicated that thousands of variations of metrics being used. Information about the distribution of metrics' individual ef...

INTRODUCTION: A team's tactical behaviour is often quantified using metrics that relate to player locations at a given time. This spatio-temporal data is easily translated into many metrics that describe the point, line and surface relations of players and the ball over time. This study reviews the spatio-temporal metrics used in invasion game spor...

INTRODUCTION: Sports performance analysts have many metrics they can use to investigate athletic performance. The multifactorial nature of sport performance means that interactions between these metrics are potentially important. Methods typically used by sports performance analysts cannot handle many variables and their interactions - especially w...

Breast volume is a key metric in breast surgery and there are a number of different methods which measure it. However, a lack of knowledge regarding a method's accuracy and comparability has made it difficult to establish a clinical standard. We have performed a systematic review of the literature to examine the various techniques for measurement o...

The application of advanced engineering to tennis racket design has influenced the nature of the sport. As a result, the International Tennis Federation has established rules to limit performance, with the aim of protecting the nature of the game. This paper illustrates how changes to the racket affect the player-racket system. The review integrate...

Complex anthropometrics such as area and volume, can identify changes in body size and shape that are not detectable with traditional anthropometrics of lengths, breadths, skinfolds and girths. However, taking these complex with manual techniques (tape measurement and water displacement) is often unsuitable. Three-dimensional (3D) surface imaging s...

Use of anthropometric data to infer sporting performance is increasing in popularity, particularly within elite sport programmes. Measurement typically follows standards set by the International Society for the Advancement of Kinanthropometry (ISAK). However, such techniques are time consuming, which reduces their practicality. Schranz et al. recen...

In many sports, the maximum swing speed of a racket, club, or bat is a key performance parameter. Previous research in multiple sports supports the hypothesis of an inverse association between the swing speed and moment of inertia of an implement. The aim of this study was to rigorously test and quantify this relationship using a restricted swingin...

Many biomechanical and medical analyses rely on the availability of reliable body segment parameter estimates. Current techniques typically take many manual measurements of the human body, in conjunction with geometric models or regression equations. However, such techniques are often criticised. 3D scanning offers many advantages, but current syst...

The maximum swing speed of an implement is an important performance parameter in many sports. It is understood that moment of inertia (MOI) has an effect upon the swing speed of an implement and numerous studies have found a very similar relationship between swing speed and MOI. These different studies considered different movements which suggested...

This research is concerned with tracking tennis racket movements. Previously, stereo camera systems have been used to track markers attached to rackets, which allows for racket movements to be obtained in three-dimensions. Typically, markers are manually selected on the image plane but this can be time consuming and inaccurate. This paper discusses...

Three-dimensional surface imaging technologies have been used in the planning and evaluation of breast reconstructive and cosmetic surgery. The aim of this study was to develop a 3D surface imaging system based on the Microsoft Kinect and assess the accuracy and repeatability with which the system could image the breast. A system comprising two Kin...

The Microsoft Kinect is a cheap consumer device capable of markerless body segment tracking. While it was not originally designed for research applications, studies have been performed which utilise its capabilities. In order to better define the suitability of the device in a clinical and biomechanical context, a study was performed which assessed...

A major component of total resistive force in cycling is aerodynamic drag. For speeds greater than ~14 m/s aerodynamic drag accounts for approximately 90% of total resistive force (Debraux et al., 2009: International Journal of Sports Medicine, 30, 266-272). Together with the air density, the coefficient of drag and the velocity of the cyclist-bike...

Since the introduction of the Microsoft Kinect in November 2010, low cost consumer depth cameras have rapidly increased in popularity. Their integral technology provides a means of low cost 3D scanning, extending its accessibility to a far wider audience. Previous work has shown the 3D data from consumer depth cameras to exhibit fundamental measure...

Breast volume has been identified as a key metric in assessing patients for reconstructive surgery. Scanning systems have measured breast volume but they have tended to rely on expensive hardware and software. This paper discusses the development and assessment of an algorithm capable of calculating breast volume from 3D point data. A mannequin was...

This paper investigates the nature of the power point in tennis. A series of static racket impacts and a polynomial fit were used to simulate four different racket shots with increasing amounts of angular velocity—identifying the true ‘power point’ for each shot. A rigid body model was used to define the ‘ideal point’ for each shot—the impact point...

As a bluff object, a football experiences high aerodynamic drag when flow is laminar due to early boundary layer separation and a large low-pressure region. The length and depth of a football’s seams can influence the separation point by triggering a turbulent boundary layer at lower Reynolds numbers. Football manufacturers can control a football’s...

The objective of this study was to assess the suitability of the Microsoft Kinect depth camera as a tool in segment scanning, segment tracking and player tracking. A mannequin was scanned with the Kinect and a laser scanner. The geometries were truncated to create torso 'segments' and compared. Separate shoulder abduction (- 100° to 50°) and flexio...

The application of advanced engineering to tennis racket design has influenced the nature of the sport. As a result, the International Tennis Federation has established rules to limit performance, with the aim of protecting the nature of the game. This paper illustrates how changes to the racket affect the player-racket system. The review integrate...

In many sports, the maximum swing speed of a racket, club or bat is a key performance parameter. Previous research has suggested that a logarithmic relationship exists between the resultant swing speed and the swing weight/moment of inertia of the implement. However, these studies have only focussed on one specific sport and relatively little is kn...

Researchers are often interested in tracking object movement in sport. This could be useful to identify equipment designs that match the technique of players. Previously, stereo camera systems have been used to track markers attached to striking implements to measure their movement in three dimensions. However, manual selection of markers on the im...

Published research on field hockey equipment is scarce. The aim of this research was to investigate methods for characterising the impact performance of field hockey sticks. Three sticks were used with fundamental frequencies in the range 74–154 Hz. Striking an initially still ball with a stick was identified as the preferred method for characteris...

Many biomechanical analyses rely on the availability of reliable body segment inertia parameter (BSIP) estimates. Current processes to obtain these estimates involve many time consuming manual measurements of the human body, used in conjunction with models or equations. While such methods have become the accepted standard they contain many inherent...

This study quantifies the accuracy of the Microsoft Kinect in two motions. Ten participants were asked to perform reaching and throwing actions which were recorded simultaneously by a Kinect and a motion analysis corporation (MAC) capture system. Elbow and shoulder angles were calculated for both motions. NITE (PrimeSense, USA) and IPI soft trackin...

There has been little three-dimensional (3D) analysis of the interaction of a tennis ball and racket during realistic play conditions. This paper is a descriptive study of elite players in practice conditions. The method used records racket and ball movement in 3D, intrudes minimally into the player’s environment and has a high level of portability...

Previous experimental studies into the dynamics of a ball–racket impact have recorded ball velocities and trajectories in one or two dimensions. These studies were limited in terms of possible impact positions and the ability to represent realistic impact conditions. As the number of dimensions in an experiment increases, it becomes difficult to is...

Wind tunnels have been used extensively to obtain the aerodynamic characteristics of many objects, including sports balls. However, as an expensive piece of equipment, wind tunnels are not always appropriate. This paper describes a method which was used to obtain a football’s coefficient of drag (Cd) profile without the use of a wind tunnel. A foot...

Software designed to quickly and easily calculate the 3-dimensional speed and the spin rate of a tennis ball from high speed video footage from a single camera was validated. The software values were compared to speed values from light gates and spin rate values found by manually tracking the ball logo. The respective ranges were 18–31 ms−1 and 65–...

Will this year's World Cup be won by a team that copes best with the way altitude affects the movement of a soccer ball?

This paper contains the recorded shot movements of 13 players in practice conditions at the Wimbledon 2006 Qualifying Tournament. A 2-camera 3D system was used to track the racket and ball for a period of 0.02 seconds for each recorded shot. Custom-written analysis software was used to extract the required co-ordinates from the ball and racket posi...

We succeeded in obtaining PSP (Pressure-Sensitive Paint) measurements for a rugby ball. It was found that the seam of the ball is the trigger for initiating low pressure. Therefore, a slower spinning ball fluctuates during flight because of the asymmetrical pressure distribution on the sides of the ball. Based on the results from PSP measurements,...

Although qualitative shot analysis and rudimentary 2D player testing has been performed in the past, a comprehensive 3D study has yet to be done. This paper outlines a method that has been used to record player baseline shots and serves in 3D. The method allows accurate tracking of racket velocity (any point on racquet), ball velocity, impact insta...