Validity and reliability of inertial measurement units used to measure motion of the lumbar spine: A systematic review of individuals with and without low back pain.

Low back pain (LBP) is a leading cause of disability, resulting in aberrant movement. This movement is difficult to measure accurately in clinical practice and gold standard methods, such as optoelectronic systems involve the use of expensive laboratory equipment. Inertial measurement units (IMU) offer an alternative method of quantifying movement that is accessible in most environments. However, there is no consensus around the validity and reliability of IMUs for quantifying lumbar spine movements compared with gold standard measures. The aim of this systematic review was to establish concurrent validity and repeated measures reliability of using IMUs for the measurement of lumbar spine movements in individuals with and without LBP. A systematic search of electronic databases, incorporating PRISMA guidelines was completed, limited to the English language. 503 studies were identified where 15 studies met the inclusion criteria. Overall, 305 individuals were included, and 109 of these individuals had LBP. Weighted synthesis of the results demonstrated root mean squared differences of <2.4° compared to the gold standard and intraclass correlations >0.84 for lumbar spine movements. IMUs offer clinicians and researchers valid and reliable measurement of motion in the lumbar spine, comparable to laboratory methods, such as optoelectronic motion capture for individuals with and without LBP.

E-Textiles for Sports and Fitness Sensing: Current State, Challenges, and Future Opportunities.

E-textiles have emerged as a fast-growing area in wearable technology for sports and fitness due to the soft and comfortable nature of textile materials and the capability for smart functionality to be integrated into familiar sports clothing. This review paper presents the roles of wearable technologies in sport and fitness in monitoring movement and biosignals used to assess performance, reduce injury risk, and motivate training/exercise. The drivers of research in e-textiles are discussed after reviewing existing non-textile and textile-based commercial wearable products. Different sensing components/materials (e.g., inertial measurement units, electrodes for biosignals, piezoresistive sensors), manufacturing processes, and their applications in sports and fitness published in the literature were reviewed and discussed. Finally, the paper presents the current challenges of e-textiles to achieve practical applications at scale and future perspectives in e-textiles research and development.

Validity, reliability, minimal detectable change, and methodological considerations for HHD and portable fixed frame isometric hip and groin strength testing: A comparison of unilateral and bilateral testing methods.

OBJECTIVES: Comparative assessment of bilateral (KangaTech) and unilateral (HHD) testing modalities through concurrent validity and test-retest reliability. Methodological considerations explored include minimum repetitions and comparison of average and maximum values. DESIGN: Experimental, observational. SETTING: Biomechanics laboratory. PARTICIPANTS: Thirty-three participants. MAIN OUTCOME MEASURES: Concurrent validity using peak force. Test-retest reliability used Abduction and Adduction using 2 trials, randomised between devices. Maximum peak force and average of both trials were used. RESULTS: HHD and KT360 are concurrently valid (r = 0.996); with no significant difference (z = -0.681). Excellent HHD reliability (ICC:0.92-0.96) and KT360 (ICC:0.89-0.97). Significant difference between max peak force and average peak force but within the calculated MDC(%). No significant differences between max peak force between trials. Spearman-Brown prophecy predicted excellent reliability for one trial (ICC:0.81-0.95). Bilateral facilitation was demonstrated using the KT360 with 94.6-101.2% increase in force compared to HHD. CONCLUSIONS: With no significant difference between first and second max effort, and excellent prophesised reliability, one rep max effort should be acceptable to use. Body positioning within the KT360 seems to elicit bilateral facilitation rather than deficit, therefore unilateral and bilateral force values are not interchangeable.

In vivo through-range passive stiffness of the lumbar spine: a meta-analysis of measurements and methods.

Passive spinal stiffness is an important property thought to play a significant role in controlling spinal position and movement. Measuring through-range passive stiffness in vivo is challenging with several methods offered in the literature. Currently, no synthesis of values or methods exists to which to compare literature to. This study aims to provide a contemporary review and quantitative synthesis of the through-range in vivo passive lumbar spinal stiffness values for each of the cardinal planes of movement. A structured systematic search, following PRISMA guidelines, of 28 electronic databases was conducted in 2022. Articles were restricted to peer-reviewed English language studies investigating in vivo through-range passive stiffness of the lumbar spine. Thirteen studies were included, ten relating to flexion/extension, four to lateral bending and five to axial rotation. Average stiffness values, as weighted means and confidence intervals, for each of the four sections of the moment-movement curves were synthesised for all planes of movement. Lateral bending was found to be the comparatively stiffest movement followed by flexion and then axial rotation. Future research should focus on the validity and reliability of measurement techniques. Axial rotation would also benefit from further study of its latter stages of range.

Limb specific training magnitude and asymmetry measurement to discriminate between athletes with and without unilateral or bilateral lower limb injury history.

OBJECTIVES: This study investigates the use of tibia-mounted inertial measurement units (IMUs) as an alternative to upper trunk-mounted IMUs for assessing lower limb training magnitudes and asymmetries in Badminton players. DESIGN: Cross-Sectional Study. SETTING: Youth athlete training environment. PARTICIPANTS: Thirty-three adolescent Badminton players, grouped based on injury history (non-injured = 19, bilateral = 6, unilateral = 8). MAIN OUTCOME MEASURES: Players wore 1 upper trunk-mounted and 2 tibia-mounted IMUs during simulated match-play. Modified vector magnitudes were assessed to identify if the IMUs can discriminate between injury history groups to assess the device location sensitivity, determine to what extent players exhibit movement asymmetry within the sport, and explore if asymmetries exist within groups with injury history. RESULTS: Upper trunk-mounted IMUs could not distinguish between injury history groups. Statistically significant asymmetries were observed in the non-injured group, however these were below the 10% threshold for clinical asymmetry. No significant asymmetries were observed in the bilaterally injured group, while statistically significant asymmetries were observed in the unilaterally injured group, which were above the 10% threshold for clinical asymmetry. CONCLUSION: These results suggest that direct limb specific IMU measurement offers a method to suitably assess training magnitudes and asymmetry within a sporting performance, rather than isolated non-sport specific testing.

A randomised observational study of individualised variations in the start position of the closed-kinetic chain upper extremity stability test.

OBJECTIVES: To assess the reliability, precision and differences between scores produced using the standard 36″ start position and 3 modified start positions of the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), towards normalisation to the individual. DESIGN: RCT of 4 conditions. SETTING: Clinical. PARTICIPANTS: Thirty-four asymptomatic individuals. MAIN OUTCOME MEASURES: Using an RCT method, variations in CKCUEST starting hand position were tested using hand spacing at standard 36″, 50% height, bi-acromial distance, and bi-acromial distance with reach to 36″. The average number of touches over 3 × 15 s maximal efforts were used to assess the intra-variation reliability, minimum detectable change (MDC) and differences to the standard 36″ start position. RESULTS: The most reliable variation was the 50% height (ICC: 0.93) and with the smallest MDC (14%). 36″ results were second-most reliable (ICC: 0.90), with a low MDC (19%). Significant differences were found between bi-acromial and 50% height to the 36″ standard setup. CONCLUSIONS: A setup position where the hand separation is 50% of the individual's height offers excellent repeated measures reliability and the smallest MDC, suggesting it is the most sensitive to change and is a recommendation to clinicians. Conversion calculations between start variations are presented.

An Exploration of the Mechanism of Action of an Equine-Assisted Intervention.

Though long alluded to, there is now an accumulation of evidence of the vital contribution that emotion makes to learning. Within this broad advance in understanding is a growing body of research emphasising the embodied nature of this emotion-based learning. The study presented here is a pilot study using a mixed-method approach (combining both physiological and experiential methodologies) to give a picture of the "emotional landscape" of people's learning through the intervention under study. This has allowed researchers to examine mediating pathways that may underlie any effects of an equine-assisted intervention. This study specifically focuses on examining the role of emotion. The intervention under study was used with young people with chronic mental health and behavioural problems for whom talk-based interventions were not working. Nine healthy participants aged 18-24 undertook the equine intervention, with an initial group having emotion-related psycho-physiological changes (skin conductance responses) measured while viewing their experience on video, and a further two participants experiencing a development of the methodology as their physiological responses were captured in real time during the intervention. The sessions were analysed by a group of five cross-disciplinary researchers to determine when significant learning episodes occurred, and the findings were that this learning was associated with powerful skin conductance responses. The qualitative element of the research entailed the participants watching themselves on video undertaking the equine intervention. They were asked to stop the video and share any changes in emotion at any point while watching. All participants experienced a positive temporal change in mood as the intervention progressed. All results supported the findings that emotional arousal occurred in relation to the participants asking the horse to perform a task. This paper will offer two novel contributions: (1) description of a new methodology for investigating the mechanism of action occurring in this type of intervention and (2) findings from the exploration of the intervention via psycho-physiological and experiential mechanisms.

The influence of lower-limb prostheses technology on Paracanoeing time-trial performance.

Within the Paracanoeing discipline, it is important to ensure that appropriate control is achieved by a paddler with a disability. However, this Paralympic Games discipline has seen very little attention to date. The aims of this study were to understand the kinematic impact to a paracanoeist when not utilizing the use of a prosthetic lower-limb. A kayaker with a uni-lateral transfemoral amputation completed several 200 m maximal efforts both with and without their prosthesis. When the prosthetic limb was removed, there were significant differences found in stroke rate, stroke speed, stroke length and overall power output. Sagittal and frontal video analysis demonstrated the residual limb movements when paddling and indicated where support would be required to improve the kayak's control. It is recommended that those with lower-limb absence wishing to paddle a kayak competitively utilize the use of a prostheses designed for the kayaking environment that supports the residual limb at both the upper and inner thigh and the distal end. Implications for rehabilitation This paper is the first study to investigate both biomechanical and assistive technology-related issues in the new Paralympic Games sport of Paracanoeing. For participants possessing lower-limb absence, a prosthetic limb that is designed specifically for the kayaking environment is recommended when Paracanoeing to maximize efficient propulsion. Use of an ergometer and multiple 2D cameras provides practitioners the ability to optimize both the comfort and fit of a prosthetic limb. Use of an ergometer and multiple 2D cameras provides both athletes and practitioners the ability to optimize the points of human contact within a kayak to ensure comfort and control.

Identification of temporal factors related to shot performance for indoor recurve archery.

The purpose of this study was to investigate the temporal phases of the archery shot cycle that distinguish the arrows distance from centre, in an attempt to understand critical factors that affect performance. Fifteen archers of varying ability each performed 30 shots at 18 m. Fourteen potential predictor variables were measured for statistical modelling by stepwise multiple linear regression. The results show that pre-shot time (pre-performance routine), follow-through time (post-performance routine), aiming time, speed of the arrow and the %variation in clicker-release time, account for 7.7% of the variation in predicting shot performance. The results have implications for practice demonstrating factors that coaches should focus on to develop their athletes. Further work on pre-, but more importantly, post-performance routines are needed generally within sport research as they are lacking and have been shown to be important contributing factors in a number of sports.

Increasing walking among older people: A test of behaviour change techniques using factorial randomised N-of-1 trials.

OBJECTIVE: Evaluations of techniques to promote physical activity usually adopt a randomised controlled trial (RCT). Such designs inform how a technique performs on average but cannot be used for treatment of individuals. Our objective was to conduct the first N-of-1 RCTs of behaviour change techniques with older people and test the effectiveness of the techniques for increasing walking within individuals. DESIGN: Eight adults aged 60-87 were randomised to a 2 (goal-setting vs. active control) × 2 (self-monitoring vs. active control) factorial RCT over 62 days. The time series data were analysed for each single case using linear regressions. MAIN OUTCOME MEASURES: Walking was objectively measured using pedometers. RESULTS: Compared to control days, goal-setting increased walking in 4 out of 8 individuals and self-monitoring increased walking in 7 out of 8 individuals. While the probability for self-monitoring to be effective in 7 out of 8 participants was beyond chance (p = .03), no intervention effect was significant for individual participants. Two participants had a significant but small linear decrease in walking over time. CONCLUSION: We demonstrate the utility of N-of-1 trials for advancing scientific enquiry of behaviour change and in practice for increasing older people's physical activity.

Measuring kinematic variables in front crawl swimming using accelerometers: a validation study.

Objective data on swimming performance is needed to meet the demands of the swimming coach and athlete. The purpose of this study is to use a multiple inertial measurement units to calculate Lap Time, Velocity, Stroke Count, Stroke Duration, Stroke Rate and Phases of the Stroke (Entry, Pull, Push, Recovery) in front crawl swimming. Using multiple units on the body, an algorithm was developed to calculate the phases of the stroke based on the relative position of the body roll. Twelve swimmers, equipped with these devices on the body, performed fatiguing trials. The calculated factors were compared to the same data derived to video data showing strong positive results for all factors. Four swimmers required individual adaptation to the stroke phase calculation method. The developed algorithm was developed using a search window relative to the body roll (peak/trough). This customization requirement demonstrates that single based devices will not be able to determine these phases of the stroke with sufficient accuracy.

Sprint prostheses used at the Paralympics: a proposal for an assessment method to maintain fairness.

BACKGROUND: Unique to sport with a disability such as those performed at the Paralympics, the need to improve the performance of lower limb prostheses can conflict with the need to provide an equal opportunity to win whilst still needing to encourage and maximise participation. OBJECTIVES: This paper extends previous research by attempting to propose a method suitable for sports governing bodies to help any functional assessment of sprinting lower limb prosthesis technology in the future. STUDY DESIGN: The study comprises two elements: 1) A historical review and evaluation of drop jump assessment techniques. 2) A pilot test of a candidate using two mechanically different lower limb regions. METHODS: A unilateral drop jump technique is assessed historically as an evaluation technique for sprinters with a lower-limb amputation. Further, a unilateral drop jump using mechanically altered lower limbs is piloted. RESULTS: The historical review provides no evidence to suggest that this technique is not suitable for athlete participants. The pilot trials show a statistically stable and repeatable method of demonstrating a mechanical deficiency of one limb to another. Six jumps are suitable to obtain stable results but the mechanical behaviour of one limb may eventually change based on accumulated fatigue. CONCLUSIONS: The unilateral drop jump is shown to be viable for application to an athlete population with a lower limb unilateral amputation.