Jon Roberts - Academia.edu (original) (raw)

Papers by Jon Roberts

Research paper thumbnail of Evaluation of vibrotactile sensations in the ‘feel’ of a golf shot

Journal of Sound and Vibration, 2005

Players' subjective perceptions of the characteristics, suitability and quality of sports equipme... more Players' subjective perceptions of the characteristics, suitability and quality of sports equipment will have a significant bearing on their equipment selection. The 'feel' of a golf club is such a perception and the vibration at impact perceived by the player is generally considered to contribute significantly to 'feel'. The aim of this study was to investigate the correlation between golfers' subjective perceptions of the feel of a shot and the post-impact vibration of a club. Suitable test procedures were developed to quantify the golfers' perceptions and to obtain measurements of vibration at the hands. The five feel characteristics investigated, 'pleasantness', 'hardness', 'solidity', 'liveliness' and perceived vibration level, were found to be strongly correlated; shots that were regarded as having a pleasant feel were also rated as having felt solid, lively, soft and with little vibration perceived. When these ratings were correlated with raw measurements of impact vibration, the relationships were initially weak. Techniques, such as normalizing the data, weighting the data and using mean data, were developed resulting in much stronger correlations. Ultimately, a reduction in the total r.m.s. vibration level was found to correlate well with the players' subjective descriptions of 'pleasant', 'solid', 'lively' and 'soft' feel.

Research paper thumbnail of Evaluation of impact sound on the ‘feel’ of a golf shot

Journal of Sound and Vibration, 2005

The 'feel' of a golf club is an important characteristic that has a significant influence on a go... more The 'feel' of a golf club is an important characteristic that has a significant influence on a golfer's choice of equipment. The sound from impact varies between different clubs and balls and this has been found to contribute to the feel of a shot. The aim of this study was to investigate the relationship between the impact sound and elite golfers' subjective perceptions of the shot. Suitable test procedures were developed to quantify the golfers' perceptions using a questionnaire and to measure the impact sound from the same shots. Statistical techniques were then employed to identify correlations between parameters of the impact sound and the golfers' subjective ratings. The characteristics sharpness and loudness of sound and pleasantness and liveliness of feel were found to be strongly correlated; a shot was rated as having a pleasant feel if it had a loud, sharp sound and a lively feel. Strong positive correlations were also obtained between the subjective ratings and parameters of the impact sound such as sound pressure level, loudness level (according to ISO 532) and sharpness.

Research paper thumbnail of Measurement of contact time in short duration sports ball impacts: an experimental method and correlation with the perceptions of elite golfers

Sports Engineering, 2001

The perception of 'feel' during a ball-implement impact is considered a significant determinant i... more The perception of 'feel' during a ball-implement impact is considered a significant determinant in equipment selection. Previous studies in golf have found that the perceived time for which the ball and clubface are in contact is a factor in the 'feel' of the shot. This factor appears to have become more significant with the development of the latest metal 'woods'. The purpose of this study was to investigate whether golfers' perceptions of impact duration correspond to measured values or whether the perceptions are created by other factors. A technique has been developed to measure the duration of impact by creating an electrical circuit in which the ball and clubface form a 'switch', completing the circuit whilst contact is maintained between the two bodies. Measurements were taken of the duration of impact between five different types of clubhead and two different constructions of golf ball. Further tests, also reported in this paper, investigated the effect of both clubhead speed at impact and ball compression on the impact duration. The results suggest that the ball has a greater effect on impact duration than the type of clubhead with lower compression balls producing longer impact durations than higher compression balls and two piece balls producing shorter impact durations than three piece, wound balls. It was also found that the duration of impact decreased as the clubhead speed at impact was increased. Finally, results suggest that there is no correlation between the perception of the golfer and the actual duration of impact and therefore other factors are responsible for creating this perception.

Research paper thumbnail of How valid and accurate are measurements of golf impact parameters obtained using commercially available radar and stereoscopic optical launch monitors?

Measurement, 2017

The application of measurement technology in golf is increasing. In particular, measures of golf ... more The application of measurement technology in golf is increasing. In particular, measures of golf performance are valuable to coaches, golfers, club-fitters and equipment manufacturers. Commercially available launch monitors, such as the TrackMan Pro IIIe and Foresight GC2+HMT, offer bespoke instantaneous methods to measure such parameters. Uncertainty in the outputs, however, is not well established nor independently verified. This study aimed to determine the degree of agreement between parameters from two launch monitors with measurements taken using a benchmark system. A total of 240 shots were collected with a driver, 7-iron and utility wedge. Shots were simultaneously tracked by each system and outputs compared using Limits of Agreement analysis. In addition, two reference grades were defined based on different levels of agreement; research and coaching grade. Agreement between the launch monitors and the benchmark system was noticeably stronger for ball parameters with greater variability in clubhead parameters. Furthermore, for both launch monitors, the strength of agreement for several parameters varied between clubs. The majority of ball parameters from both launch monitors fell within the research reference grade, but caution is needed for the use of clubhead parameters within a research environment. For coaches and clubfitters, the results suggest the launch monitor parameters are largely of sufficient quality.

Research paper thumbnail of Just Noticeable Differences in the Length of Golf Irons

Proceedings, 2020

Current custom fitting guidelines for golf clubs suggest the smallest change in club length from ... more Current custom fitting guidelines for golf clubs suggest the smallest change in club length from a standard length iron should be 6 mm (1/4”). However, no previous research suggests why this length change is used. This study aims to identify the minimum noticeable difference in the length of 7-iron clubs using just noticeable difference analysis techniques. Fifty golfers of varying ability were asked to compare a standard length 7-iron to test 7-irons of varying lengths, regarding changes in the perception of club length and body position at address. Irrespective of golfing ability, golfers could perceive a just noticeable difference of 13 mm (1/2”) from the standard length club. However, when asked if changes in body position were present, category 1 golfers noticed differences with a 6 mm change in club length and category 2 golfers noticed differences with a 13 mm change. No changes in body position were perceived by highly handicapped golfers.

Research paper thumbnail of Professional golf coaches’ perceptions of the key technical parameters in the golf swing

Procedia Engineering, 2012

Assessing a coach's technical knowledge of a sporting technique can reveal measureable biomechani... more Assessing a coach's technical knowledge of a sporting technique can reveal measureable biomechanical parameters associated with successful performance. This assessment can provide new insights into technique, enhance a coach's technical knowledge or assist in optimising performance. Despite numerous golf instructional books, no scientific study has assessed a golf coach's technical knowledge of the golf swing. Therefore, the purpose of this study was to identify the key technical parameters that professional golf coaches associate with a top level golf swing; with the intention of using the results to guide future golf biomechanics research and coaching technologies. Initially, sixteen professional golf coaches were individually observed coaching a highly skilled golfer after which they participated in a semi-structured interview regarding their technical analysis of the golf swing. QSR-NVivo analysis software was used to inductively analyse the data using the grounded theory approach. Line-by-line coding was followed by comparison of 'meaning units' to form a coding hierarchy with several key technical parameters identified. A successful golf swing was defined through three elements, with "body motion" affecting "club motion" and resulting "ball flight". Several terms described these parameters including "consistent", "powerful", "accurate", "simple" and "controlled" with the most prevalent being "repeatable". "Body motion" was influenced by five intrinsically linked key technical parameters: "posture", "body rotation", "sequential movement", "hand and arm action" and "club parameters" which were further sub categorised. To conclude, the key technical parameters have been identified which will be used to support future biomechanical research in this area and to be used to direct new technologies to aid golf coaching.

Research paper thumbnail of Evaluation of vibrotactile sensations in the ‘feel’ of a golf shot

Journal of Sound and Vibration, 2005

Players' subjective perceptions of the characteristics, suitability and quality of sports equipme... more Players' subjective perceptions of the characteristics, suitability and quality of sports equipment will have a significant bearing on their equipment selection. The 'feel' of a golf club is such a perception and the vibration at impact perceived by the player is generally considered to contribute significantly to 'feel'. The aim of this study was to investigate the correlation between golfers' subjective perceptions of the feel of a shot and the post-impact vibration of a club. Suitable test procedures were developed to quantify the golfers' perceptions and to obtain measurements of vibration at the hands. The five feel characteristics investigated, 'pleasantness', 'hardness', 'solidity', 'liveliness' and perceived vibration level, were found to be strongly correlated; shots that were regarded as having a pleasant feel were also rated as having felt solid, lively, soft and with little vibration perceived. When these ratings were correlated with raw measurements of impact vibration, the relationships were initially weak. Techniques, such as normalizing the data, weighting the data and using mean data, were developed resulting in much stronger correlations. Ultimately, a reduction in the total r.m.s. vibration level was found to correlate well with the players' subjective descriptions of 'pleasant', 'solid', 'lively' and 'soft' feel.

Research paper thumbnail of Evaluation of impact sound on the ‘feel’ of a golf shot

Journal of Sound and Vibration, 2005

The 'feel' of a golf club is an important characteristic that has a significant influence on a go... more The 'feel' of a golf club is an important characteristic that has a significant influence on a golfer's choice of equipment. The sound from impact varies between different clubs and balls and this has been found to contribute to the feel of a shot. The aim of this study was to investigate the relationship between the impact sound and elite golfers' subjective perceptions of the shot. Suitable test procedures were developed to quantify the golfers' perceptions using a questionnaire and to measure the impact sound from the same shots. Statistical techniques were then employed to identify correlations between parameters of the impact sound and the golfers' subjective ratings. The characteristics sharpness and loudness of sound and pleasantness and liveliness of feel were found to be strongly correlated; a shot was rated as having a pleasant feel if it had a loud, sharp sound and a lively feel. Strong positive correlations were also obtained between the subjective ratings and parameters of the impact sound such as sound pressure level, loudness level (according to ISO 532) and sharpness.

Research paper thumbnail of Measurement of contact time in short duration sports ball impacts: an experimental method and correlation with the perceptions of elite golfers

Sports Engineering, 2001

The perception of 'feel' during a ball-implement impact is considered a significant determinant i... more The perception of 'feel' during a ball-implement impact is considered a significant determinant in equipment selection. Previous studies in golf have found that the perceived time for which the ball and clubface are in contact is a factor in the 'feel' of the shot. This factor appears to have become more significant with the development of the latest metal 'woods'. The purpose of this study was to investigate whether golfers' perceptions of impact duration correspond to measured values or whether the perceptions are created by other factors. A technique has been developed to measure the duration of impact by creating an electrical circuit in which the ball and clubface form a 'switch', completing the circuit whilst contact is maintained between the two bodies. Measurements were taken of the duration of impact between five different types of clubhead and two different constructions of golf ball. Further tests, also reported in this paper, investigated the effect of both clubhead speed at impact and ball compression on the impact duration. The results suggest that the ball has a greater effect on impact duration than the type of clubhead with lower compression balls producing longer impact durations than higher compression balls and two piece balls producing shorter impact durations than three piece, wound balls. It was also found that the duration of impact decreased as the clubhead speed at impact was increased. Finally, results suggest that there is no correlation between the perception of the golfer and the actual duration of impact and therefore other factors are responsible for creating this perception.

Research paper thumbnail of How valid and accurate are measurements of golf impact parameters obtained using commercially available radar and stereoscopic optical launch monitors?

Measurement, 2017

The application of measurement technology in golf is increasing. In particular, measures of golf ... more The application of measurement technology in golf is increasing. In particular, measures of golf performance are valuable to coaches, golfers, club-fitters and equipment manufacturers. Commercially available launch monitors, such as the TrackMan Pro IIIe and Foresight GC2+HMT, offer bespoke instantaneous methods to measure such parameters. Uncertainty in the outputs, however, is not well established nor independently verified. This study aimed to determine the degree of agreement between parameters from two launch monitors with measurements taken using a benchmark system. A total of 240 shots were collected with a driver, 7-iron and utility wedge. Shots were simultaneously tracked by each system and outputs compared using Limits of Agreement analysis. In addition, two reference grades were defined based on different levels of agreement; research and coaching grade. Agreement between the launch monitors and the benchmark system was noticeably stronger for ball parameters with greater variability in clubhead parameters. Furthermore, for both launch monitors, the strength of agreement for several parameters varied between clubs. The majority of ball parameters from both launch monitors fell within the research reference grade, but caution is needed for the use of clubhead parameters within a research environment. For coaches and clubfitters, the results suggest the launch monitor parameters are largely of sufficient quality.

Research paper thumbnail of Just Noticeable Differences in the Length of Golf Irons

Proceedings, 2020

Current custom fitting guidelines for golf clubs suggest the smallest change in club length from ... more Current custom fitting guidelines for golf clubs suggest the smallest change in club length from a standard length iron should be 6 mm (1/4”). However, no previous research suggests why this length change is used. This study aims to identify the minimum noticeable difference in the length of 7-iron clubs using just noticeable difference analysis techniques. Fifty golfers of varying ability were asked to compare a standard length 7-iron to test 7-irons of varying lengths, regarding changes in the perception of club length and body position at address. Irrespective of golfing ability, golfers could perceive a just noticeable difference of 13 mm (1/2”) from the standard length club. However, when asked if changes in body position were present, category 1 golfers noticed differences with a 6 mm change in club length and category 2 golfers noticed differences with a 13 mm change. No changes in body position were perceived by highly handicapped golfers.

Research paper thumbnail of Professional golf coaches’ perceptions of the key technical parameters in the golf swing

Procedia Engineering, 2012

Assessing a coach's technical knowledge of a sporting technique can reveal measureable biomechani... more Assessing a coach's technical knowledge of a sporting technique can reveal measureable biomechanical parameters associated with successful performance. This assessment can provide new insights into technique, enhance a coach's technical knowledge or assist in optimising performance. Despite numerous golf instructional books, no scientific study has assessed a golf coach's technical knowledge of the golf swing. Therefore, the purpose of this study was to identify the key technical parameters that professional golf coaches associate with a top level golf swing; with the intention of using the results to guide future golf biomechanics research and coaching technologies. Initially, sixteen professional golf coaches were individually observed coaching a highly skilled golfer after which they participated in a semi-structured interview regarding their technical analysis of the golf swing. QSR-NVivo analysis software was used to inductively analyse the data using the grounded theory approach. Line-by-line coding was followed by comparison of 'meaning units' to form a coding hierarchy with several key technical parameters identified. A successful golf swing was defined through three elements, with "body motion" affecting "club motion" and resulting "ball flight". Several terms described these parameters including "consistent", "powerful", "accurate", "simple" and "controlled" with the most prevalent being "repeatable". "Body motion" was influenced by five intrinsically linked key technical parameters: "posture", "body rotation", "sequential movement", "hand and arm action" and "club parameters" which were further sub categorised. To conclude, the key technical parameters have been identified which will be used to support future biomechanical research in this area and to be used to direct new technologies to aid golf coaching.