Rebecca Mellifont

The use of a single inertial sensor to identify stride, step, and stance durations of running gait.

Current developments in inertial sensor technology could enable the measurement of running gait outside of the traditional laboratory environment. The purpose of this research was to determine the level of agreement between an inertial sensor and infrared camera based estimates of stride, step, and stance durations across a range of running speeds. An inertial sensor was placed on the sacrum of 10 elite national standard runners, and the stride, step, and stance of running gait were compared. A total of 504 samples were collected and the running velocities stratified into three equal groups of low (10-12 km/h), medium (13-15 km/h), and high (16-19 km/h). A single inertial sensor was found to be suitable for identifying stride duration with Bland-Altman limits of agreement of 95%. The stride data showed agreement at less than 0.02s for most limits. Agreement for step showed five of the eight upper and lower limits below 0.02s. The largest differences between both capture methods were for stance. An average bias of 0.0008s was found and standard error ranged between 0.0004s and 0.0009s across all variables. The results from this research found that inertial sensors are suitable to measure stride, step, and stance duration, and provide the opportunity to measure running gait outside of the traditional laboratory.

Detection of Illegal Race Walking: A Tool to Assist Coaching and Judging

Current judging of race walking in international competitions relies on subjective human observation to detect illegal gait, which naturally has inherent problems. Incorrect judging decisions may devastate an athlete and possibly discredit the international governing body. The aim of this study was to determine whether an inertial sensor could improve accuracy, monitor every step the athlete makes in training and/or competition. Seven nationally competitive race walkers performed a series of legal, illegal and self-selected pace races. During testing, athletes wore a single inertial sensor (100 Hz) placed at S1 of the vertebra and were simultaneously filmed using a high-speed camera (125 Hz). Of the 80 steps analyzed the high-speed camera identified 57 as illegal, the inertial sensor misidentified four of these measures (all four missed illegal steps had 0.008 s of loss of ground contact) which is considerably less than the best possible human observation of 0.06 s. Inertial sensor comparison to the camera found the typical error of estimate was 0.02 s (95% confidence limits 0.01–0.02), with a bias of 0.02 (±0.01). An inertial sensor can thus objectively improve the accuracy in detecting illegal steps (loss of ground contact) and, along with the ability to monitor every step of the athlete, could be a valuable tool to assist judges during race walk events.

Sport Science and Coaching in Paralympic Cycling

This research documents the sport science initiatives of the Australian Cycling team in preparation for the 2004 Athens Paralympic Games. The research was driven by the head coach of the cycling program with biomechanical and physiological measures made during competition and/or in a controlled laboratory for six Paralympic cyclists. Half the group modified their setup with seat height decreases within a range of 10–19 mm, the other half with seat height increases within a range or 3–12 mm. All riders required seat fore/aft positioning adjustments of up to 30 mm forward to centre the knee joint over the pedal spindle. The pelvic angle rotation changed by an average of 7 degrees positive tilt (range 5–14 degrees). Relatively simple adjustments to one individuals setup reduced the cyclists frontal-surface height by 0.22 m, with no significant change in power output. The integration of sport science with a high-performance coaching program can enhance the athletes performance and safety. The outcomes of this specific research on elite athletes with a disability have guided the future coaching of the national team

The influence of dive direction on the movement characteristics for elite football goalkeepers

This study biomechanically quantified the movement patterns for six elite goalkeepers making diving saves to their preferred and non-preferred side at three different dive heights. Synchronised three-dimensional kinematic and kinetic biomechanical data analysis found diving direction to significantly (P < 0.05) influence the movement patterns of the diving save. The non-preferred side displayed greater lateral rotation of the pelvis and thorax at the initiation event. These over-rotational differences were reduced during the time on plate phase with the thorax displaying no significant difference at take-off; although a difference still remained for the pelvis. These over rotations were subsequently linked to greater peak knee joint moments, lower peak ankle joint moments, less hip extension at take-off, and for the centre of mass (COM) to travel slower and less directly to the ball, as measured by the net projection angle at take-off. These results indicate that joint movements in the transverse plane at or before the initiation event for the dive for the pelvis and thorax are the causation for subsequent asymmetries. These observed differences indicate that there is an advantage in having prior knowledge of limb preference in an opposing goalkeeper.

Sports technology provides an objective assessment of the Paralympic swimming classification system

The Paralympic Games are the highest form of competition for an athlete with a disability and the fundamental distinction between the Olympic and Paralympic Games is the Paralympic classification system. Recently the International Paralympic Committee mandated the development of an evidence-based classification system for each sport. To create an objective Paralympic classification system this study firstly evaluated the current classification musculoskeletal protocols with swimming specific equipment. To mitigate against the numerous physical variations in people with a disability, 32 elite able-bodied swimmers were assessed. Using a custom-built bilateral swim bench ergometer and a 3D Motion Monitor (120 Hz) system, upper-limb kinematic and performance measures (hand force) were collected and compared to the musculoskeletal protocols. There were inconsistent and generally weak correlations between the current classification system range of motion scores, and the actual 3D kinematic range of motion, with similar weak correlations to hand force. Although not evident in the relatively static musculoskeletal protocols, important swimming specific asymmetry differences were identified in shoulder abduction/adduction along with external rotation, via the sports technology assessment. These findings highlight firstly the deficiencies in the current classification system, followed by the advantages of implementing sport-specific technology to objectively address this international issue.

Improving balance in community‐dwelling older people through a targeted mediolateral postural stability program

pairment (dementia or delirium) was found. Given that postoperative pain after hip fracture in older patients has been associated with longer length of stay, delayed ambulation, and long-term functional impairment and that severe pain significantly increases the risk of delirium in cognitively intact patients, proactive pain management is warranted for patients with cognitive impairment and for patients with certain types of surgical treatment of hip fracture.

Clinical Assessment of Scapula Motion: Scapula Upward Rotation and Relationship with Injury in Swimmers

Abnormal scapulothoracic mechanics and scapulohumeral rhythm are implicated in shoulder pathologies, including glenohumeral impingement and rotator cuff tears. Upward scapula rotation, specifically asymmetry of scapula motion and associations of patterns through range with injury, was investigated in dominant and non-dominant limbs of nationally ranked junior and Paralympic swimmers during competition season. The static and throughout phases measures of upward scapula rotation were: Phase I (start position, 45°), Phase II (45° to 90°), Phase III (90° to 135°) and Phase IV (135° to max). Injury was assessed with a validated questionnaire. Differences between side (dominant and non-dominant), group (junior and Paralympic), and phase were examined. Significant differences (P < 0.05) between groups were identified for dominant side at rest, 45° and 135°, and in phases II and IV (including range). Scapulohumeral rhythm was higher in the non-dominant limb of Paralympic swimmers but in the dominant limb of junior swimmers. Greatest differences in upward rotation between injured and non-injured swimmers were found in Phase 1: 43.6% (3.3°) Paralympic; 73.1% (8°) junior. Results suggest asymmetry of movement in both limbs, through all phases, and at single points in range, should be investigated for assessing injury and developing preventive strategies and rehabilitation protocols.