Trevor J Allen

Monash University (Australia) · Monash University Accident Research Centre (MUARC)

The sense of limb position is important, because it is believed to contribute to our sense of self-awareness. Muscle spindles, including both primary and secondary endings of spindles, are thought to be the principal position sensors. Passive spindles possess a property called thixotropy which allows their sensitivity to be manipulated. Here, thixo...

Context We describe baseline and preliminary follow-up data of a study aimed at improving injury surveillance data quality of hospitals contributing to the Victorian Emergency Minimum Dataset (VEMD). Process Sequential study phases included baseline data quality analysis, direct engagement and communication with ED hospital sites, collection of su...

Objective Safely negotiating curves with a powered-two-wheeler (PTW) requires a high level of skill, and a significant proportion of PTW crashes have a curve involvement. This study aimed to estimate the applicability, potential benefits and feasibility of novel Motorcycle Curve Assist (MCA). The system is designed to operate an emergency control o...

The role of powered two-wheeler (PTW) transport from the perspective of a more sustainable mobility system is undermined by the associated high injury risk due to crashes. Motorcycle-based active safety systems promise to avoid or mitigate many of these crashes suffered by PTW riders. Despite this, most systems are still only in the prototype phase...

Objective: In this paper, we describe the design and baseline data of a study aimed at improving injury surveillance data quality of hospitals contributing to the Victorian Emergency Minimum Dataset (VEMD). Methods: The sequential study phases include a baseline analysis of data quality, direct engagement and communication with each of the emerg...

Objective Recent field-tests on Motorcycle Autonomous Emergency Braking system (MAEB) showed that higher levels of deceleration to improve its effectiveness were feasible. However, the potential of MAEB in mitigating rider injuries is not well understood, particularly in scenarios where the efficacy of standard MAEB is limited because the rider is...

Ten adult participants carried out two experiments on position sense at the forearm, one a two-arm matching task, the other a one-arm pointing task. For matching, both forearms were strapped to paddles which moved in the vertical plane between 0° and 90°. At the start of each trial, the arms were conditioned with a contraction sequence to control f...

Effort, force and heaviness are related terms, having in common that they are all sensations associated with the generation of voluntary muscle contractions. Traditionally they have been thought to originate in the brain, as a result of copies of motor commands relayed to sensory areas. A stumbling block for the central hypothesis has been the lack...

Isometric exercise is often prescribed during rehabilitation from injury in order to maintain muscle condition and prevent disuse atrophy. However such exercise can lead to muscle soreness and damage. Here we investigate which parameters of isometric contractions are responsible for the damage. Bouts of 30 repetitions of maximum voluntary contracti...

Introduction The increased popularity of powered two wheelers (PTWs) in Australia, combined with their vulnerability in the event of a crash, necessitates new strategies to prevent serious injury crashes. The purpose of this study was to use case-series data collected from a recent motorcycle case-control study to analyse contributing factors to cr...

The impact that muscle fatigue and taping have on proprioception in an applied sporting context remains unclear. The purpose of this study was to investigate disturbances in position sense at the shoulder joint, and asses the effectiveness of adhesive tape in preventing injury and improving performance, after a bout of cricket fast bowling. Among a...

Position sense at the human elbow joint has traditionally been measured in blindfolded subjects using a forearm matching task. Here we compare position errors in a matching task with errors generated when the subject uses a pointer to indicate the position of a hidden arm. Evidence from muscle vibration during forearm matching supports a role for m...

Objective: Autonomous emergency braking (AEB) is a safety system that detects imminent forward collisions and reacts by slowing down the host vehicle without any action from the driver. AEB effectiveness in avoiding and mitigating real-world crashes has recently been demonstrated. Research suggests that a translation of AEB to powered 2-wheelers co...

Objective: The purpose of this study was to describe the nature and extent of current powered two-wheeler (PTW) risk exposures in order to support future efforts to improve safety for this mode of transport. Methods: A cross sectional analysis of the control arm of a population based case control study was conducted. The control sample was selec...

The purpose of this study was to measure carbon monoxide (CO) exposure at an Australian motor sport endurance event

The purpose of this study was to compare the effect of Unleaded and E85 on carbon monoxide (CO) exposure at an Australian motor sport endurance event

The purpose of this study was to compare the effect of two different fuels (Unleaded and E85) on carbon monoxide (CO) exposure at an Australian motor sport endurance event

The purpose of this study was to compare the effect of two different fuels (Unleaded and 85% Ethanol/15% Unleaded) on carbon monoxide (CO) exposure at an Australian motor sport (Adelaide 500) endurance event over two consecutive years (2008, 2009).

The purpose of this study was to compare the effect of two different fuels (Unleaded and 85% Ethanol/15% Unleaded) on carbon monoxide (CO) exposure at an Australian motor sport (Adelaide 500) endurance event over two consecutive years (2008, 2009).

The purpose of this study was to compare the effect of two different fuels (Unleaded and 85% Ethanol/15% Unleaded) on carbon monoxide (CO) exposure at an Australian motor sport (Adelaide 500) endurance event over two consecutive years (2008, 2009).

The purpose of this study was to compare the effect of two different fuels (Unleaded and 85% Ethanol/15% Unleaded) on carbon monoxide (CO) exposure at an Australian motor sport (Adelaide 500) endurance event over two consecutive years (2008, 2009).

The purpose of this study was to compare the effect of two different fuels (Unleaded and 85% Ethanol/15% Unleaded) on carbon monoxide (CO) exposure at an Australian motor sport (Adelaide 500) endurance event over two consecutive years (2008, 2009).

Key points: Position sense at the human forearm can be measured in blindfolded subjects by matching positions of the arms or by a subject pointing to the perceived position of an unseen arm. Effects on position sense tested were: elbow muscle conditioning with a voluntary contraction, muscle vibration, loading the arm and elbow skin stretch. Condi...

Current knowledge on safety technologies developed for passenger cars represents great potential for translatable solutions that may also reduce the number and the severity of casualties among motorcyclists. However, the translation of a safety system conceived for a four-wheeled vehicle to a motorcycle is not straightforward due to the different c...

These experiments were designed to test the idea that, in a forearm position-matching task, it is the difference in afferent signals coming from the antagonist muscles of the forearm that determines the perceived position of the arm. In one experiment, flexor and then extensor muscles of the reference arm were conditioned by isometric voluntary con...

The traditional view of the neural basis for the sense of muscle force is that it is generated at least in part within the brain. Recently it has been proposed that force sensations do not arise entirely centrally and that there is a contribution from peripheral receptors within the contracting muscle. Evidence comes from experiments on thumb flexo...

When a muscle relaxes after a contraction, cross-bridges between actin and myosin in sarcomeres detach, but about 1 % spontaneously form new, non-force-generating attachments. These bridges give muscle its thixotropic property. They remain in place for long periods if the muscle is left undisturbed and give the muscle a passive stiffness in respons...

Most studies of exercise-induced muscle injury have focussed on eccentric contractions, which are known to produce damage and delayed soreness. It is less well known that isometric contractions also produce damage and soreness. This is a study of the damaging effects of isometric exercise. To investigate the contributions of factors such as muscle...

Key points When a blindfolded subject holds his or her arm at a particular angle, its reported position shifts over time; this is known as proprioceptive drift. Here, we show that in relation to position sense at the elbow, the direction of perceived shifts is consistent with adaptation in discharge levels of sensory receptors in elbow muscles. Rai...

Recent studies suggested that centrally-generated motor commands contribute to perception of position and movement at the wrist, but not the elbow. Because the wrist and elbow experiments used different methods, this study was designed to resolve the discrepancy. Two methods were used to test both the elbow and wrist (20 subjects each). For the wri...

The present-day view of the neural basis for the senses of muscle force and heaviness is that they are generated centrally, within the brain, from copies of motor commands. A corollary of the motor discharge generates a sense of effort which underlies these sensations. In recent experiments on force and heaviness sensations using thumb flexor muscl...

Background Motorcycle sales, registration and use are increasing in many countries. The epidemiological literature on risk factors for motorcycle injury is becoming outdated, due to changes in rider demography, licensing regulations, traffic mix and density, road environments, and motorcycle designs and technologies. Further, the potential contribu...

We reported previously that concentric or eccentric exercise can lead to errors in human limb position sense. Our data led us to conclude that the errors, post-exercise, were not due to an altered responsiveness of the proprioceptive afferents, and we proposed that they resulted from central changes in the processing of the afferent input. However,...

Introduction Provision of adequate chest compressions remains a standard of care for optimal outcome in cardiopulmonary arrest. Given the recent changes to CPR rates and a greater emphasis on pushing faster and deeper, this has raised questions surrounding rescuer fatigue and efficacy of compressions. While a body of work has been undertaken on pre...

We have previously shown, in a two-limb position-matching task in human subjects, that exercise of elbow flexors of one arm led the forearm to be perceived as more extended, while exercise of knee extensors of one leg led the lower leg to be perceived as more flexed. These findings led us to propose that exercise disturbs position sense because sub...

The study measured the effect of stretch on passive mechanical properties in unexercised and eccentrically exercised plantarflexor muscles, to obtain insight into how stretch might serve athletes as a warm-up strategy. Passive torque, voluntary contraction strength and muscle soreness were measured before and after a large amplitude stretch given b...

In experiments on position sense at the elbow joint in the horizontal plane, blindfolded subjects were required to match the position of one forearm (reference) by placement of their other arm (indicator). Position errors were measured after conditioning elbow muscles of the reference arm with an isometric contraction while the arm was held either...

This is a report of the effects of exercise on position matching at the knee. Young adult subjects were required to step down a set of stairs (792 steps), representing eccentric-biased exercise of the quadriceps muscle, or step up them, concentric-biased exercise. Immediately after eccentric exercise subjects showed a mean force drop of 28% (+/- 6%...

The purpose of this study was to determine the effect of eccentric exercise on the ability to exert steady submaximal forces with muscles that cross the elbow joint. Eight subjects performed two tasks requiring isometric contraction of the right elbow flexors: a maximum voluntary contraction (MVC) and a constant-force task at four submaximal target...

In a forearm position-matching task in the horizontal plane, when one (reference) arm is conditioned by contraction and length changes, subjects make systematic errors in the placement of their other, indicator arm. Here we describe experiments that demonstrate the importance not just of conditioning the reference arm, but of the indicator arm as w...

Eccentric exercise can produce damage to muscle fibres. Here damage indicators are measured in the medial gastrocnemius muscle of the anaesthetised cat after eccentric contractions on the descending limb of the muscle's length-tension relation, compared with eccentric contractions on the ascending limb and concentric contractions on the descending...

When blindfolded subjects match the position of their forearms in the vertical plane they rely on signals coming from the periphery as well as from the central motor command. The command signal provides a positional cue from the accompanying effort sensation required to hold the arm against gravity. Here we have asked, does a centrally generated ef...

This is a study of the ability of blindfolded human subjects to match the position of their forearms before and after eccentric exercise. The hypothesis tested was that the sense of effort contributed to forearm position sense. The fall in force after the exercise was predicted to alter the relationship between effort and force and thereby induce p...

We have recently shown that in an unsupported forearm-matching task blindfolded human subjects are able to achieve an accuracy of 2-3 degrees . If one arm was exercised to produce significant fatigue and the matching task was repeated, it led subjects to make position-matching errors. Here that result is confirmed using fatigue from a simple weight...

To assess the contribution of central and peripheral factors to changes in maximum voluntary force and its length dependence after eccentric muscle damage, voluntary and twitch torque were measured across a wide angular range, along with voluntary activation using twitch interpolation. Isometric torque from both maximum voluntary contractions (MVCs...

Experiments were carried out to test the hypothesis that, in the absence of vision, position sense at the human forearm is generated by the combined input from muscle spindles in elbow flexor muscles and signals of central origin giving rise to a sense of effort. In a forearm position-matching task, to remove a possible contribution from the sense...

Various exercises are used to retrain the abdominal muscles in the management of low back pain and other musculoskeletal disorders. However, few studies have directly investigated the activity of all the abdominal muscles or the recruitment of regions of the abdominal muscles during these manoeuvres. This study examined the activity of different re...

Skeletal muscle weakness and atrophy occur following an extended period of decreased use, including space flight and limb unloading. It is also likely that affected muscles will be susceptible to a re-loading injury when they begin return to earth or weight bearing. However, there is a paucity of literature evaluating the response of human unloaded...

Evidence is provided for a mechanical event as the first step in the process leading to muscle damage after a series of eccentric contractions. Aspects discussed include the decline in active tension, increase in passive tension, shift in length-tension relation, soreness, swelling, and disturbed proprioception.

Clinical measurement of pelvic floor muscle activity commonly involves techniques that are both physically and psychologically invasive. This study investigated transabdominal application of ultrasound to measure pelvic floor muscle action. The specific aims were to establish the face validity of ultrasound measures of displacement of the posterior...

Many advances in the field of exercise physiology have occurred during the past decade. This latest edition of the Textbook of Work Physiology continues the winning formula of earlier editions—providing an up-to-date resource that covers all aspects of applied work and exercise physiology. Although it is perhaps most suited to exercise physiologist...

The purpose of the present study was to compare the effectiveness of instruction to contract the pelvic floor muscles (PFM), the transversus abdominis (TrA), and the TrA + PFM visualized as displacement of the pelvic floor by ultrasound. Twenty female physical therapists, mean age 41.1 years (range 26-56) participated in the study. A 3.5 MHz 35 mm...

It is known that a period of eccentric exercise provides protection against damage to muscle from subsequent eccentric exercise. Here we ask, does concentric exercise do the opposite, make muscle more prone to damage? The triceps surae muscle group of one leg in each of eight human subjects was subjected to 30 min of concentric exercise per day, fo...

Following a series of eccentric contractions, that is stretching of the muscle while generating active tension, the length-tension relationship of isolated amphibian muscle has been shown to shift towards longer muscle length (Katz 1939; Wood et al. 1993). Here we report observations of electrically stimulated ankle extensor muscles of nine human s...