VISUAL ASSESSMENT TOOLS IN TENNIS

The ability to analyse high-speed strokes in tennis is at least in-part dependant on a coach’s ability to ‘see’ the critical features of the stroke being analysed. While the ‘eye’ provides visual feedback of the highest order, there are times when technology can play an important role in assisting a coach to observe specific body movements or alternatively to present ‘pictures of performance’ to a player. Visual feedback is an integral part of performance feedback. This paper will discuss the different visual approaches that may be used by coaches. A relatively recent development the high-speed opto-reflective motion analysis system, has offered an alternate research design investigating tennis stroke production. Using such a system, results from a service analysis of high performance players will be presented in an endeavour to better understand the inter-relationship between the legs and the trunk in the tennis serve

Sea Beam Survey of an Active Strike-Slip Fault: The San Clemente Fault in the California Continental Borderland

The San Clemente fault, located in the California Continental Borderland, is an active, northwest trending, right-lateral, wrench fault. Sea Beam data are used to map the major tectonic landforms associated with active submarine faulting in detail unavailable using conventional echo-sounding or seismic reflection data. In the area between North San Clemente Basin and Fortymile Bank, the major late Cenozoic faults are delineated by alignments of numerous tectonic landforms, including scarps, linear trenches, benches, and sags. Character and spatial patterns of these landforms are consistent with dextral wrench faulting, although vertical offsets may be substantial locally. The main trace of the San Clemente fault cuts a straight path directly across the rugged topography of the region, evidence of a steeply dipping fault surface. Basins or sags located at each right step in the en echelon pattern of faults are manifestations of pull-apart basin development in a right-slip fault zone. Seismic reflection profiles show offset reflectors and a graben in late Quaternary turbidites of the Navy Fan, where the fault zone follows a more northerly trend. Modern tectonic activity along the San Clemente fault zone is demonstrated by numerous earthquakes with epicenters located along the fault\u27s trend. The average strike of the San Clemente fault is parallel to the predicted Pacific-North American relative plate motion vector at this location. Therefore we conclude that the San Clemente fault zone is a part of the broad Pacific-North American transform plate boundary and that the southern California region may be considered as a broad shear zone

TRANSVERSE AND FRONTAL PLANE LOWER LIMB 'KINEMATICS IN FEMALE RUNNERS WITH PATELLOFEMORAL PAIN

Patellofemoral pain syndrome (PFPS), one of the most common disorders in running has been shown to affect females more frequently than males. The aetiology of patellofemoral pain syndrome is not clear but abnormat hip and ,knee frontal and transverse plane motion are commonly associated with the disorder. This study investigated transverse and frontal plane kinematics and kinetics in female runners symptomatic and asymptomatic for patellofemoral pain. The findings of this study did not reflect the common clinically held association between excessive femoral intemal rotation, internal tibial rotation and knee valgus in runners with PFPS. The PFPS subjects displayed greater external hip and external knee rotation compared with asymptomatic runners. The results have identified a different set of mechanical conditions which may affect patella tracking

ILLEGAL BOWLING ACTIONS LAWS, DO THEY REALLY MATTER?

The purpose of this study was to compare performance variables and upper body kinematics between cohorts of pathway (illegal and legal action) and elite level (legal) finger-spin (FS) bowlers. Results indicated that pathway illegal bowlers place significantly more revolutions on the ball compared with bowlers of the same level, reflecting that of the higher elite level bowlers. These differences are driven by various upper body kinematic differences at the trunk, elbow and wrist. This research highlights that when bowling with an illegal action, a possible performance benefit exists, reinforcing the current illegal action laws (the law does matter)

FIELD VERSUS LABORATORY TESTING IN SPORTS BIOMECHANICS: SYSTEM AND MODELLING ERRORS

The sport biomechanist is often challenged to ‘test performance’ during competition and not in the laboratory environment. While ecological validity of data must always be of concern, measurement error (both system, and modelling) and the characteristics of equipment used (manual or automatic?), often mean that data are collected under ‘simulated match’ conditions. This paper will review the vexing question of laboratory versus field testing from a biomechanical perspective. Current data suggest that for movements involving out of plane rotations, laboratory testing with an opto-reflective system (cluster based model), provides a more accurate measure of elbow angle when compared with the same angle collected with a video-based system (vector model) during a simulated cricket bowling task

The conjunctival fungal microflora of horses in a North Queensland tropical environment and their in vitro susceptibilities to antifungal agents

Fungi are ubiquitous in the environment and part of the commensal microflora on the conjunctiva of equine eyes. North Queensland, being tropical, presents an ideal environment for fungi growth. When the cornea is injured, fungi can invade the corneal stroma, resulting in keratomycosis. The objectives of this study were to determine the fungal species specific to the eyes of horses in the Townsville region; to investigate the potential risk factors associated with the presence of fungi; and to test their susceptibility to antifungals to create an empirical guide for treatment. The eyes of forty ophthalmologically normal horses from James Cook University were sampled throughout the summer months of December 2017, January 2018, and January and February 2020. Cultured fungi were identified morphologically, and their identity confirmed by comparing partial 18sRNA DNA sequences with the NCBI nucleotide database. Minimum inhibitory concentration testing of common antifungal medications was performed. Sixty-one out of eighty conjunctival samples grew fungi, and 21 different fungi genera were isolated. The most common genera were Aspergillus (18%, 26/141), Curvularia (14%,20/141), Rhodotorula (12%,17/141) and Penicillium (12%,17/141). No significant association was found between age or environmental factors and fungal culture status. Most fungi were highly susceptible to voriconazole and ketoconazole but resistant to fluconazole and amphotericin B. This adds to the body of evidence on which species of fungi are present as normal ocular microflora of horses living in tropical regions of Australia, and an avenue for treating them

FUNCTIONAL SCREENING TEST ASSOCIATED WITH ALTERED TRUNK AND PELVIS KINEMATICS AND LOW BACK INJURY INCIDENCE IN ADOLESCENT FAST BOWLERS

This study investigated the relationship between pelvi-femoral stability and low back injury incidence in adolescent fast bowlers using the single leg decline squat test, and examined the relationship between knee kinematics during this clinical test and bowling kinematics during the delivery stride. Twenty-five uninjured male fast bowlers participated in a prospective cohort study. Bowlers who suffered a low back injury had significantly increased knee valgus angle during the single leg decline squat on the dominant leg (8.6° ±3.2 vs 4.5° ±2.6, t=3.495, p=0.002) and non-dominant leg (9.1° ±4.2 vs 5.5° ±3.3, t=2.362, p=0.027). Increased knee valgus angle during the test was associated with increased frontal plane hip and knee motion, pelvis rotation and thorax lateral flexion during bowling, which may lead to increased torsional stress on the lumbar spine

THE INFLUENCE OF KNEE JOINT FLEXION-EXTENSION ON WRIST JOINT SPEED IN CRICKET FAST BOWLERS

The purpose of this study was to assess the sensitivity of wrist joint velocity to manipulations of knee joint flexion–extension kinematic waveforms through the use of a forward kinematic approach. The bowling kinematics of twelve male cricket pace bowlers were entered into a forward kinematic model using MATLAB software. The participants‘ knee joint flexion-extension kinematics were manipulated in two ways: 1) offset by ± 20° and 2) amplified by a factor of ± 2. Both manipulations led to increases in resultant wrist joint velocity at the time of ball release. An offset of 20° extension increased wrist joint velocity by 5.6% whereas an amplification factor of 2 increased wrist joint velocity by 29.9%. These results support the notion that a flexor-extender knee joint technique is ideal for cricket pace bowlers