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Although research has leaned toward an external focus, there is no consensus on the optimal distance of the attentional focus for novice learners. The purpose of this study was to examine which type of attentional focus is beneficial for the novices performing golf putting task. Forty-five novice learners (23 males, 22 females), aged 20 to 37, participated in this study. Participants were randomized into the attentional focus of attention (FOA) conditions of internal (i.e., focus on the arm movement), external-proximal (i.e., focus on the golf club), and external-distal (i.e., focus on the target). Each participant was requested to perform four blocks of 10 putts on an artificial putting surface. The total number of putts made, total putt points achieved, and perceived confidence for each putt were recorded. A 4 (block) × 3 (condition) mixed-design analysis of variance was applied for data analysis. The external-proximal FOA condition had significantly better performance (i.e., more putt points) than the external-distal FOA condition. Under the internal FOA condition, participants significantly made more golf putt points during the third and fourth blocks than the first block. Perceived confidence was significantly elevated during the third block and fourth block compared to the first block across all conditions. Postexperimental manipulation check showed most participants adopted the focus as they were instructed. The external-distal FOA may be detrimental for novice learners in skill acquisition. Putting performance was related to the perceived confidence for the golf stroke. Therefore, it is recommended that practitioners consider the OPTIMAL theory by facilitating external-proximal FOA and the motivational factor together for novice learners.

The purpose of this study was to examine the distance of varying focus of attention for experienced and novice golfers on a golf putting task. Forty-eight experienced and 48 novice golfers were randomized into four attentional focus conditions: control (no instruction), internal (i.e., focus on the arm movement), external proximal (i.e., focus on the golf club), and external distal (i.e., focus on the target) conditions. Performance outcomes (the perceived level of confidence and number of golf putts made) were recorded. Experienced golfers had better performance outcomes than novice golfers. The external proximal focus was specifically beneficial for novice golfers, while experienced golfers had an advantage in both external focus instructions. The external proximal focus might enable a perception-action process for novice golfers to compare the relationship between action planning and the surrounding environment. In addition, the transition to expertise might result in no difference between both external focus instructions for experienced golfers.

Garvin’s seminal work “What Does ‘Product Quality’ Really Mean?” defines product quality based on five approaches: transcendent, product-based, user-based, manufacturing-based, and value-based. In addition to presenting five definitions of product quality, Garvin presents eight dimensions of product quality: performance, features, reliability, conformance, durability, serviceability, aesthetics, and perceived quality. The purpose of this research is to present a taxonomy for establishing product quality metrics for basketball shoes based on Garvin’s eight dimensions and the user-based definition of product quality. There is no clear explanation for what constitutes a properly fitted and usable basketball shoe. Constructing a multi-dimensional basketball shoe quality taxonomy, as presented in this paper, captures relationships between features and user needs to improve the fitness for use in basketball shoes beyond commonly-used marketing jargon. Several contextual relationships of basketball are identified and associated with the requirements of basketball players, thereby resulting in a basketball shoe quality taxonomy that defines the relationships of shoe features to user preference. This taxonomy can be used to derive what product quality means to the basketball athlete and thus improve the decision-making process for the basketball shoe wearer and coaching staff.

Wearables are a multi-billion-dollar business with more growth expected. Wearable technology is fully entrenched at multiple levels of athletic competition, especially at the National Collegiate Athletic Association (NCAA) and professional levels where these solutions are used to gain competitive advantages by assessing health and performance of elite athletes. However, through the National Science Foundation (NSF) Innovation Corps (I-Corps) training experience, a different story emerged based on pilot interviews from coaches and trainers regarding the lack of trust in wearables, and how the technology falls short of measuring what practitioners need. An NSF I-Corps project was funded to interview over 100 strength and conditioning coaches (S&CCs) and athletic trainers (ATs) regarding the current state of wearables at the NCAA and professional levels. Through 113 unstructured interviews, a conceptual map of relationships amongst themes and sub-themes regarding wearable technology emerged through the grouping of responses into meaning units (MUs). Interview findings revealed that discussions by S&CCs and ATs regarding wearables could be grouped into themes tied to (a) the organizational environment, (b) the athlete, and (c) the analyst or data scientist. Through this project, key findings and lessons learned were aggregated into sub-themes including: the sports ecosystem and organizational structure, brand development, recruiting, compliance and gamification of athletes, baselining movement and injury mitigation, internal and external loads, “return tos,” and quantifying performance. These findings can be used by practitioners to understand general technology practices and where to close the gap between what is available versus what is needed.

This paper presents a retrospective of the benchmark testing methodologies developed and accumulated into the stretch sensor tool kit (SSTK) by the research team during the Closing the Wearable Gap series of studies. The techniques developed to validate stretchable soft robotic sensors (SRS) as a means for collecting human kinetic and kinematic data at the foot-ankle complex and at the wrist are reviewed. Lessons learned from past experiments are addressed, as well as what comprises the current SSTK based on what the researchers learned over the course of multiple studies. Three core components of the SSTK are featured: (a) material testing tools, (b) data analysis software, and (c) data collection devices. Results collected indicate that the stretch sensors are a viable means for predicting kinematic data based on the most recent gait analysis study conducted by the researchers (average root mean squared error or RMSE = 3.63°). With the aid of SSTK defined in this study summary and shared with the academic community on GitHub, researchers will be able to undergo more rigorous validation methodologies of SRS validation. A summary of the current state of the SSTK is detailed and includes insight into upcoming experiments that will utilize more sophisticated techniques for fatigue testing and gait analysis, utilizing SRS as the data collection solution.

Wearable sensors are beneficial for continuous health monitoring, movement analysis, rehabilitation, evaluation of human performance, and for fall detection. Wearable stretch sensors are increasingly being used for human movement monitoring. Additionally, falls are one of the leading causes of both fatal and nonfatal injuries in the workplace. The use of wearable technology in the workplace could be a successful solution for human movement monitoring and fall detection, especially for high fall-risk occupations. This paper provides an in-depth review of different wearable stretch sensors and summarizes the need for wearable technology in the field of ergonomics and the current wearable devices used for fall detection. Additionally, the paper proposes the use of soft-robotic-stretch (SRS) sensors for human movement monitoring and fall detection. This paper also recapitulates the findings of a series of five published manuscripts from ongoing research that are published as Parts I to V of “Closing the Wearable Gap” journal articles that discuss the design and development of a foot and ankle wearable device using SRS sensors that can be used for fall detection. The use of SRS sensors in fall detection, its current limitations, and challenges for adoption in human factors and ergonomics are also discussed.

A novel wearable solution using soft robotic sensors (SRS) has been investigated to model foot-ankle kinematics during gait cycles. The capacitance of SRS related to foot-ankle basic movements was quantified during the gait movements of 20 participants on a flat surface as well as a cross-sloped surface. In order to evaluate the power of SRS in modeling foot-ankle kinematics, three-dimensional (3D) motion capture data was also collected for analyzing gait movement. Three different approaches were employed to quantify the relationship between the SRS and the 3D motion capture system, including multivariable linear regression, an artificial neural network (ANN), and a time-series long short-term memory (LSTM) network. Models were compared based on the root mean squared error (RMSE) of the prediction of the joint angle of the foot in the sagittal and frontal plane, collected from the motion capture system. There was not a significant difference between the error rates of the three different models. The ANN resulted in an average RMSE of 3.63, being slightly more successful in comparison to the average RMSE values of 3.94 and 3.98 resulting from multivariable linear regression and LSTM, respectively. The low error rate of the models revealed the high performance of SRS in capturing foot-ankle kinematics during the human gait cycle.

The purpose of this study was to evaluate the use of compressible soft robotic sensors (C-SRS) in determining plantar pressure to infer vertical and shear forces in wearable technology: A ground reaction pressure sock (GRPS). To assess pressure relationships between C-SRS, pressure cells on a BodiTrakTM Vector Plate, and KistlerTM Force Plates, thirteen volunteers performed three repetitions of three different movements: squats, shifting center-of-pressure right to left foot, and shifting toes to heels with C-SRS in both anterior&ndash, posterior (A/P) and medial&ndash, lateral (M/L) sensor orientations. Pearson correlation coefficient of C-SRS to BodiTrakTM Vector Plate resulted in an average R-value greater than 0.70 in 618/780 (79%) of sensor to cell comparisons. An average R-value greater than 0.90 was seen in C-SRS comparison to KistlerTM Force Plates during shifting right to left. An autoregressive integrated moving average (ARIMA) was conducted to identify and estimate future C-SRS data. No significant differences were seen in sensor orientation. Sensors in the A/P orientation reported a mean R2 value of 0.952 and 0.945 in the M/L sensor orientation, reducing the effectiveness to infer shear forces. Given the high R values, the use of C-SRSs to infer normal pressures appears to make the development of the GRPS feasible.

Background: An induced loss of balance resulting from a postural perturbation has been reported as the primary source for postural instability leading to falls. Hence, early detection of postural instability with novel wearable sensor-based measures may aid in reducing falls and fall-related injuries. The purpose of the study was to validate the use of a stretchable soft robotic sensor (SRS) to detect ankle joint kinematics during both unexpected and expected slip and trip perturbations. Methods: Ten participants (age: 23.7 &plusmn, 3.13 years, height: 170.47 &plusmn, 8.21 cm, mass: 82.86 &plusmn, 23.4 kg) experienced a counterbalanced exposure of an unexpected slip, an unexpected trip, an expected slip, and an expected trip using treadmill perturbations. Ankle joint kinematics for dorsiflexion and plantarflexion were quantified using three-dimensional (3D) motion capture through changes in ankle joint range of motion and using the SRS through changes in capacitance when stretched due to ankle movements during the perturbations. Results: A greater R-squared and lower root mean square error in the linear regression model was observed in comparing ankle joint kinematics data from motion capture with stretch sensors. Conclusions: Results from the study demonstrated that 71.25% of the trials exhibited a minimal error of less than 4.0 degrees difference from the motion capture system and a greater than 0.60 R-squared value in the linear model, suggesting a moderate to high accuracy and minimal errors in comparing SRS to a motion capture system. Findings indicate that the stretch sensors could be a feasible option in detecting ankle joint kinematics during slips and trips.

Background: Assessment of basketball shoes as personal protection equipment (PPE) at the collegiate level is unique. Objective: The purpose of Part I in this pilot study was to examine the effect of shoe design on jump height in elite male and female National Collegiate Athletic Association (NCAA) Division 1 basketball student-athletes. Method: Each team selected two pairs of AdidasTM branded shoes. The male student-athletes selected the AdidasTM Harden Vol. 3 and the AdidasTM SM Pro basketball shoes. The female student-athletes selected the AdidasTM Harden Vol. 3 and the AdidasTM Captain Marvel basketball shoes. A total of sixteen basketball student-athletes (six males, ten females) performed an acute series of four styled basketball jumps on two ForceDecksTM Force Platforms while trying to maximize jump height by tapping VertecTM Jump Vanes. Two trials were performed in each shoe and for each type of jump which included a countermovement jump, drop jump from 30cm, step and jump, and a series of plyometric jumps. Results: The results of this pilot study indicated a non-significant effect of basketball shoe design on jump height while performing an acute series of basketball style jumps for either the male or female basketball student-athletes. However, there were significant differences in jump height and peak power between the male and female basketball student-athletes (p = 0.001). Conclusion: In addition to the results, the use of quantitative performance testing on the effectiveness of basketball shoe designs as PPE may assist in the mitigation of non-contact ankle and lower limb injuries.

Interviews from strength and conditioning coaches across all levels of athletic competition identified their two biggest concerns with the current state of wearable technology: (a) the lack of solutions that accurately capture data &ldquo, from the ground up&rdquo, and (b) the lack of trust due to inconsistent measurements. The purpose of this research is to investigate the use of liquid metal sensors, specifically Liquid Wire sensors, as a potential solution for accurately capturing ankle complex movements such as plantar flexion, dorsiflexion, inversion, and eversion. Sensor stretch linearity was validated using a Micro-Ohm Meter and a Wheatstone bridge circuit. Sensors made from different substrates were also tested and discovered to be linear at multiple temperatures. An ankle complex model and computing unit for measuring resistance values were developed to determine sensor output based on simulated plantar flexion movement. The sensors were found to have a significant relationship between the positional change and the resistance values for plantar flexion movement. The results of the study ultimately confirm the researchers&rsquo, hypothesis that liquid metal sensors, and Liquid Wire sensors specifically, can serve as a mitigating substitute for inertial measurement unit (IMU) based solutions that attempt to capture specific joint angles and movements.

The driver is the club which receives the greatest scrutiny by golfers and the most marketing efforts by manufacturers. One characteristic often indicated and believed to effect driver performance is the degree of loft on the clubface. The purpose of the current study was to investigate the effect that the loft of a driver and gender has on golf ball launch variables and distance. The variables that were examined included club head speed, ball speed, launch angle, descent (impact) angle, total spin, carry, and total distance. Fifteen participants (12 male, 3 female) with a handicap of eight or lower were used to test three different degree drivers (9.5°, 10.5°, and 13°) on the variables listed above. Participants performed ten tested swings for each driver and the variables were measured. The data were analyzed with a two (gender) by three (club face loft) repeated-measures ANOVA. There were significant differences (p < .05) in total spin rate, descent angle, and total distance between the clubs. The male...

The purpose of this study was to use 3D motion capture and stretchable soft robotic sensors (SRS) to collect foot-ankle movement on participants performing walking gait cycles on flat and sloped surfaces. The primary aim was to assess differences between 3D motion capture and a new SRS-based wearable solution. Given the complex nature of using a linear solution to accurately quantify the movement of triaxial joints during a dynamic gait movement, 20 participants performing multiple walking trials were measured. The participant gait data was then upscaled (for the SRS), time-aligned (based on right heel strikes), and smoothed using filtering methods. A multivariate linear model was developed to assess goodness-of-fit based on mean absolute error (MAE, 1.54), root mean square error (RMSE, 1.96), and absolute R2 (R2, 0.854). Two and three SRS combinations were evaluated to determine if similar fit scores could be achieved using fewer sensors. Inversion (based on MAE and RMSE) and plantar flexion (based on R2) sensor removal provided second-best fit scores. Given that the scores indicate a high level of fit, with further development, an SRS-based wearable solution has the potential to measure motion during gait- based tasks with the accuracy of a 3D motion capture system.

The purpose of the study was to evaluate the effects of six weeks of strength/functional training on muscular strength and golf performance, measured by club-head speed. Ten participants (age = 21.4 ± 2.3 yrs) were randomly assigned to an experimental group performing 6 weeks of strength/functional training or a control group that followed their regular activity/golf routine. Club-head speed was measured as an indicator of golf performance. A 2 × 2 ANOVA with repeated measures on swing speed revealed significant (p .05) differences were noted for vertical jump or sit-and-reach. Participants realized improvements in strength during their participation but these did not translate to...

The influence of golf driver mass and shaft length on initial golf ball launch conditions was investigated. A series of carefully selected player tests were used to isolate the coupled influence of club mass and shaft length on initial ball velocity, spin rates, launch angle, and dispersion of impacts across the clubface. The ranges of selected club masses and shaft lengths were typical of those found in currently available drivers. While longer, lighter clubs generally led to higher ball speeds for most test golfers, those combinations of club mass and club length that minimized spin rates resulted in the greatest estimated total shot distance. Not surprisingly, use of longer drivers led to a slightly larger dispersion of impacts over the clubface. Interestingly, individual golfers tended to miss in the same region of the clubface irrespective of the club length, i.e., they compensated for changes in club mass and length when swinging. Employing the methodology outlined here, it may be possible to tailor golf club designs in order to obtain enhanced golf ball launch characteristics for a range of golfers. Such efforts may facilitate golf club design by establishing relationships between mass and configuration parameters that lead to improved driver performance.