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Biomedical subjects

A S McIntosh

Publications and source records attributed to A S McIntosh.

At least 19 recordsLinked to original sources
PubMed2005

The Heidelberg foot measurement method: development, description and assessment.

The aim of this study was to develop and evaluate a kinematic measurement method for the foot that could be applied clinically to measure foot function including all typical foot deformities. The ankle was modelled as two anatomically based hinge joints rotating around anatomical axes estimated by the use of projection angles. For the mid- and forefoot a descriptive approach was chosen by defining angles between anatomical landmarks or reference points derived from these landmarks. The motion of 17 markers on the lower leg and foot was measured during walking gait on 10 adult participants with no known abnormalities to determine the pattern of normal foot motion, assess reliability and provide a reference against which pathological foot behaviour could be compared. Functional angles for mid- and forefoot motions were developed to improve clinical applications of the data. The combination of anatomically and technically oriented marker placement on the foot is a reliable basis for reproducible kinematic measurements and the method was shown to be viable for clinical practice.

Adult↗
PubMed2005

Rugby World Cup 2003 injury surveillance project.

OBJECTIVES: To study match injury patterns and incidence during the Rugby World Cup 2003 (RWC 2003); to compare these patterns and rates with comparative rugby injury data; and to assess differences between teams playing at different levels (eight finalists v 12 non-finalists). METHODS: Data were collected prospectively during the tournament. All injuries were recorded by the 20 participating team physicians. These were submitted to the tournament medical officer. An injury was defined as an event which forced a player either to leave the field or to miss a subsequent game or both. RESULTS: 189 injuries were recorded over 48 matches. This corresponds to 97.9 injuries per 1000 player-hours. Pool matches yielded a higher injury rate than non-pool matches. The 12 non-finalist teams sustained significantly higher injury rates than the eight finalist teams. The player positions open side flanker, inside centre, and number 8 were the most frequently injured positions. There was a low concussion rate, which may reflect under-reporting. The non-finalist teams had a higher rate of recurrent injury. CONCLUSIONS: The injury rate was higher than comparative data. Mismatches in the areas of skill, fitness, and the availability of resources for medical care of players may explain these differences.

Athletic Injuries↗
PubMed2005

Preventing head and neck injury.

A wide range of head and neck injury risks are present in sport, including catastrophic injury. The literature since 1980 on prevention of head and neck injury in sport was reviewed, focusing on catastrophic and brain injury and identifying the range of injury prevention methods in use. There have been few formal evaluations of injury prevention methods. Approaches that are considered, or have been proven, to be successful in preventing injury include: modification of the baseball; implementation of helmet standards in ice hockey and American football and increased wearing rates; use of full faceguards in ice hockey; changes in rules associated with body contact; implementation of rules to reduce the impact forces in rugby scrums. Helmets and other devices have been shown to reduce the risk of severe head and facial injury, but current designs appear to make little difference to rates of concussion. Research methods involving epidemiological, medical, and human factors are required in combination with biomechanical and technological approaches to reduce further injury risks in sport.

Athletic Injuries↗
PubMed2003

Rugby headgear study.

A two year randomised controlled trial of headgear in Rugby Union football is being conducted in Sydney, Australia. This paper gives an overview of this study in progress and presents results related to the development and laboratory performance of the headgear. The study commenced in 2002. Participants recruited to the study are in the under 13, 15, school open (U18) and colts age groups. There are three study arms: control, IRB-approved headgear, and modified headgear. The IRB approved headgear is a popular model in rugby, the Canterbury Honeycomb model manufactured by BodyArmour in New Zealand. The dimensions of this model were altered by increasing foam density and thickness to produce the modified headgear. In impact energy attenuation tests of 15 and 20 Joules onto a flat anvil, the modified headgear demonstrated average maximum headform accelerations of 23% and 33% of the standard model, respectively. Whether or not this improvement translates into reductions in injury will be determined by a comparison of the rates and severities of head injuries across study arms. Furthermore, these dimensional changes may not be acceptable to rugby players. Player attitudes towards safety and the use of protective clothing, injury history, experience and on-field behaviour will be examined via structured pre- and end of season surveys and analysis of match video.

Adolescent↗
PubMed2003

A pilot study of the attitudes of Australian Rules footballers towards protective headgear.

Despite a relatively high risk of injury to participants of Australian Rules football, very few players report wearing protective equipment. The aim of this paper is to describe the results of a pilot survey of the attitudes of community-level Australian Rules football players towards protective headgear and the risk of head injury. Seventy players from four purposefully chosen clubs in metropolitan Melbourne completed a self-report questionnaire at the end of the 2000-playing season. Almost all players (91.4%) reported they did not wear protective headgear during the 2000 season. Non-headgear users said that headgear was too uncomfortable (47.4%) and they didn't like it (42.1%). However, 80.0% of non-users said they would wear it if it prevented injury. The major motivation for wearing headgear was to prevent injury. Players considered rugby, boxing and driving a car, to be associated with a higher-risk of head injury than Australian Rules football. As a group, the players perceived the risk of head injury in Australian Rules football to be low to moderate when compared to other sports and activities. This partially explains why so few players wore protective headgear. Repeat surveys on a larger sample should be conducted to further understand the attitudes towards protective headgear and perceptions of risk in community-level Australian football players.

Adolescent↗
PubMed2003

Evaluation of cricket helmet performance and comparison with baseball and ice hockey helmets.

BACKGROUND: Protective helmets in sport are important for reducing the risk of head and facial injury. In cricket and other sports with projectiles, national test standards control the minimum helmet performance. However, there are few field data showing if helmets are effective in reducing head injury. OBJECTIVES: (a) To examine the performance of cricket helmets in laboratory tests; (b) to examine performance with regard to test standards, game hazards, and helmet construction; (c) to compare and contrast these findings with baseball and ice hockey helmets. METHODS: Impact tests were conducted on a selection of helmet models: five cricket, two baseball, and two ice hockey. Ball to helmet impacts at speeds of 19, 27, 36, and 45 m/s were produced using an air cannon and a Hybrid III dummy headform and neck unit. Free fall drop tests with a rigid headform on to a selection of anvils (flat rigid, flat deformable, and hemispherical rigid) were conducted. Resultant headform acceleration was measured and compared between tests. RESULTS: At the lower speed impacts, all helmets produced a good reduction in headform acceleration, and thus injury risk. At the higher speed impacts, the effectiveness was less. For example, the mean maximum headform accelerations for all cricket helmets at each speed were: 67, 160, 316, and 438 g for 19, 27, 36, and 45 m/s ball speeds respectively. Drop tests on to a hemispherical anvil produced the highest accelerations. The variation in performance increased as the magnitude of the impact energy increased, in both types of testing. CONCLUSIONS: The test method used for baseball helmets in which the projectile is fired at the helmet may be superior to helmet drop tests. Cricket helmet performance is satisfactory for low speed impacts, but not for impacts at higher, more realistic, speeds. Baseball and ice hockey helmets offer slightly better relative and absolute performance at the 27 m/s ball and puck impacts.

Acceleration↗
PubMed2001

What do under 15 year old schoolboy rugby union players think about protective headgear?

OBJECTIVES: When protective headgear is designed, the attitudes of the intended users needs to be taken into account, as well as safety performance criteria. The aim of this study was therefore to determine the attitudes of schoolboy rugby union players towards protective headgear. METHODS: A survey of 140 rugby union players (82.4% response rate) from 10 randomly selected school teams in metropolitan Sydney was conducted at the end of the 1999 playing season. All players were aged 14-16 years. All teams had participated in a trial of headgear during the 1999 season in which six of the teams had been assigned to a headgear trial arm and four teams to a control arm. Players completed a self report questionnaire during a supervised session at school. The questionnaire collected information on recent head injuries, use of protective equipment, and attitudes towards headgear. RESULTS: Some form of protective equipment was always worn by 76.1% of players: 93.6% reported using a mouthguard and 79.3% a helmet/headgear during the 1999 season. The two most important reasons for wearing headgear were related to safety concerns. Players with no recent head/neck injury were more likely to report that they felt safer when wearing headgear (p<0.001) and less likely to cite a previous injury as a motivating factor for wearing headgear (p<0.001) than those who had sustained a recent head/neck injury. Of the players who wore headgear during the 1999 season, 67% said that they played more confidently when they wore headgear, but 63% said that their head was hotter. Few players reported that their head was uncomfortable (15%) or that it was hard to communicate (3%) when they wore headgear. The main reasons for not wearing headgear were related to its design features: uncomfortable (61%) and it was hot (57%). CONCLUSIONS: The primary reason cited by players for wearing headgear is safety. Receiving an injury would also motivate non-wearers to wear headgear. Players report that they are more confident and able to tackle harder if they wear headgear, suggesting that a belief in its protective capabilities may influence behaviour. These attitudes need to be addressed in the design of effective headgear as well as in strategies to promote its use.

Adolescent↗
PubMed2001

Effectiveness of headgear in a pilot study of under 15 rugby union football.

OBJECTIVE: To determine whether protective headgear reduced the incidence of concussion in a pilot study of under 15 rugby union. METHODS: Sixteen under 15 rugby union teams were recruited from three interschool competitions in metropolitan Sydney and the adjacent country region. A prospective study was undertaken over a single competitive season. The study had two arms: a headgear arm and a control arm. Headgear wearing rates and injury data were reported to the investigators and verified using spot checks. RESULTS: A total of 294 players participated in the study. There were 1179 player exposures with headgear and 357 without headgear. In the study time frame, there were nine incidences of concussion; seven of the players involved wore headgear and two did not. There was no significant difference between concussion rates between the two study arms. CONCLUSIONS: Although there is some controversy about the desirability of wearing protective headgear in football, this pilot study strongly suggests that current headgear does not provide significant protection against concussion in rugby union at a junior level.

Adolescent↗
PubMed2000

The dynamics of concussive head impacts in rugby and Australian rules football.

A study was commenced in 1998 at the University of New South Wales (UNSW) to investigate the dynamics of head impacts in football which resulted in concussion. Sixty-eight cases of medically verified concussion from Australian Rules Football and 32 from Rugby Union and Rugby League were analyzed. Video of each injury event was analyzed to obtain descriptive data regarding the head impact site and striking object. The video was analyzed quantitatively to obtain estimates of the closing speeds. A secondary analysis was undertaken using the conservation of momentum and energy relationships to estimate the change in velocity of the head during the impact, the change in momentum of the head, and the energy imparted to the head. Ninety-seven cases involved direct head contact, whereas three cases involved impulsive loading via the trunk. The majority of impacts were to the tempero-parietal region, and the striking body segment was commonly the arm or shoulder/thorax. The mean change in velocity of the head and head impact energy for all 97 cases of direct head impact were 4 m x s(-1) and 56 J, respectively. Head impact energy can be used as a performance criteria for testing and developing headgear for rugby and Australian rules football.

Athletic Injuries↗
PubMed2000

Impact energy attenuation performance of football headgear.

OBJECTIVES: Commercially available football head protectors were tested to determine their impact energy attenuation performance and ability to reduce the likelihood of concussion. METHODS: Prospective study using standardised impact test methods with both rigid (magnesium) and Hybrid III headforms. RESULTS: Eight commercially available head protectors from six manufacturers were tested. The magnitude of the headform accelerations increased as the drop height was increased, ranging from a minimum of 64 g from a height of 0.2 m to a maximum of 1,132 g from a height of 0.6 m. The head injury criterion and maximum headform acceleration values followed a similar trend. A steep increase was noted in the magnitude of maximum headform acceleration and head injury criterion when the drop height was increased from 0.4 to 0.5 m. This indicates that the foam material was completely compressed at an impact energy above about 20 J and therefore offers little protection against impacts of greater severity. Repeated tests using a drop height of 0.3 m showed that some helmets exhibit a "memory" effect, whereby impact performance is reduced by up to 50% with repeated impacts. CONCLUSIONS: Laboratory tests indicate that current commercially available football headgear performance will not reduce the likelihood of concussion. The absence of internationally recognised standards for soft headgear designed to ameliorate concussion is a major deficiency in sports injury prevention.

Craniocerebral Trauma↗
PubMed1998

Emergency endoscopic retrograde cholangiopancreatography in critically ill patients.

BACKGROUND: The aim of this study was to assess the frequency, indications, yield, and outcome of emergency endoscopic retrograde cholangiopancreatography (ERCP) in critically ill patients. METHODS: Records of all intensive care unit patients undergoing emergency ERCP were reviewed over a 40-month period. Indications, findings, therapeutic interventions, and survival were analyzed. Those requiring mechanical ventilation at the time of ERCP were in group A and those who did not were in group B. RESULTS: Of 1781 ERCPs, 32 (1.80%) were performed on intensive care unit patients. Fifteen patients belonged to group A (46.87%) and 17 (53.13%) to group B. The common bile duct was the duct of interest in 30 patients (94%) and was cannulated in 97%. Indications included possible biliary sepsis (68.75%), gallstone pancreatitis, and jaundice (12.5% each). The most common finding was choledocholithiasis (34%), followed by failure to fill the cystic duct (16%) and common bile duct stricture (9%). A normal examination was present in 18.75% of cases. Endoscopic therapy was required in 66.6% of patients in group A and 70.5% of group B. The overall 30-day mortality was 25% (33% for group A and 17.6% for group B) and not related to the ERCP. CONCLUSIONS: Two percent of all ERCPs performed were on intensive care unit patients (47% requiring mechanical ventilation) primarily to evaluate for possible biliary sepsis. Technical success was not compromised by mechanical ventilation. Therapeutic intervention was required in more than two thirds of patients and the overall 30-day mortality was 25%.

Adult↗
PubMed1987

Sodium nitroprusside: pharmacological aspects of its interaction with hydroxocobalamin and thiosulphate.

Hydroxocobalamin (HOCb), when mixed with sodium nitroprusside (SNP) in a 10:1 or 1:1 molar ratio and injected (i.v.) into the anaesthetized rat, prolonged the depressor response to SNP by 25-50%, but did not affect the degree of blood pressure lowering. Both the 'onset' and 'offset' components of the response were prolonged. Injecting [14C]SNP along with a 10-fold molar excess of HOCb resulted in a 2- to 3-fold elevation of plasma radioactivity which was maintained during the first 10 min of a 40 min experimental period. These effects of HOCb on the pharmacodynamics and pharmacokinetics of SNP are probably due to complex formation between the two compounds. Sodium thiosulphate (ST) added to SNP (12:1 molar ratio) had no effect on the depressor response to SNP. This mixing of ST and SNP had a less-marked influence on the plasma [14C] SNP-derived radioactivity than occurred with HOCb. There was no initial elevation of radioactivity, but the levels were raised by 50-60% at 4, 6 and 10 min. Since the depressor response to SNP was unaffected by ST, it is presumed that the higher concentrations of radioactivity were due to inactive degradation products rather than the active species itself.

Animals↗
PubMed1981

A case of clear cell adenocarcinoma of the vagina in pregnancy.

The case is described of a 20 year old pregnant woman with clear cell adenocarcinoma of the vagina who had been exposed to diethyl stilboestrol in utero. This is the second of three cases known to have occurred in Britain. The importance of radical treatment is discussed. Neither cervical nor vaginal intra-epithelial neoplasia were seen histologically, although squamous metaplasia was widespread, and in some areas was immature and showed atypical features which could be misinterpreted as intra-epithelial neoplasia. An area of atypical adenosis was noticed, a hitherto rarely observed feature.

Adenocarcinoma↗