Evaluation of the costs and benefits of motorcycle helmet laws

Since 1976, 28 states have repealed or significantly amended their motorcycle helmet laws. The change in legislation was not based on an evaluation of the costs and benefits of such laws. This paper attempts such an assessment by comparing the cost of motorcycle helmets with the medical costs averted due to helmet use using data primarily based on motorcycle crashes in Colorado, Oklahoma, and South Dakota. Nationwide, at least $61 million could be saved annually if all motorcyclists were to use helmets. Helmet law repeals have been observed to lead to a 40 to 50 per cent point reduction in helmet use. The associated additional medical care costs substantially exceed cost savings produced by reduced helmet use. It is estimated that helmet law repeals may produce annually between $16 and 18 million of unnecessary medical care expenditures. Several alternatives to increase motorcycle helmet use are briefly discussed. It is concluded that helmet laws are effective in encouraging helmet use among motorcyclists and will prevent unnecessary medical expenditures as well as unnecessary pain and suffering among injured motorcyclists.

Simple and microbiologically safe portable transport unit for patients requiring protected isolation

The removal of a patient from a laminar air flow room during protected isolation poses the risk of his microbial contamination and infection. Nonetheless, temporary removal from the laminar air flow room may be necessary for certain medical procedures or for psychological relief during prolonged periods of isolation or both. A means for protecting patients during temporary removal from the laminar air flow room is highly desirable. A previously described total body garment has been shown to be microbiologically safe and effective, but is expensive, cumbersome, and not very adaptable to patients of different ages and body sizes. We now present an alternative, microbiologically safe transportation system which delivers, high-efficiency particulate air-filtered air over the head and neck through a modified, lightweight, commercially available helmet and power supply and which can be comfortably and reliably used by isolated patients.

A critical evaluation of two methods of head fixation

Two head-fixation systems, one using Thermoplast and the other Lightcast were tested as to reproducibility by comparing stereotactic coordinates before and after CT scan and after removal and reapplication of the helmets. Helmets constructed of Lightcast were more consistently stable than those constructed of Thermoplast probably due in part to the dental fixation used with the former. With Lightcast the change in position of coordinates was consistently less than 3 mm, i.e. 2 pixels, which is within the tolerance of the system as a whole.

Large skull defect in a headbanger

A mentally retarded self-mutilating child developed a large skull defect at the site of repeated trauma. The bony defect involved only the outer table and had smooth bony margins.

Hats for the newborn infant

The efficacy of a Gamgee-lined hat in reducing the rate of fall in rectal temperature of infants during the first 30 minutes of life was studied. The trial, which included 211 infants, was randomised, prospective, and controlled. One hundred and seven infants were exposed to overhead radiantheaters. Of these, only 30 had normal deliveries, so the analysis was confined to the infants who were not subjected to radiant heat, and in this group no conclusions were drawn about the efficacy of a hat or a radiant heater. In the 104 infants not subjected to radiant heat, body weight, initial rectal temperature, the application of hat, the environmental temperature, and the duration of exposure while naked were all found to influence measureably the rate of fall in rectal temperature during the first 30 minutes. Gamgee-lined hats should be routinely used to minimise heat loss, especially in small infants exposed at birth, during surgical operations, and during investigations necessitating prolonged exposure.

Eye injuries in Canadian amateur hockey

Two studies, one retrospective (1972 to 1973) and one prospective (1974 to 1975), CONcerning eye injuries incurred by hockey players were conducted by the Canadian Ophthalmological Society with questionnaires to its members. Responses to the questionnaires were analyzed by age, type of injury, cause (i.e., hockey stick, puck, or other means), and results to visual acuity. The results were also designated by organized or unorganized participation. Almost 300 eye injuries were reported in each study. In the first study, 13.7% of the injured players became legally blind as a result of the injury; in the second study, 16% became legally blind. Organized hockey produced more injuries than unorganized hockey. The majority of the injuries were caused by the hockey stick. The injuries were both intraocular and extraocular. The group of 11- to 15-year olds received the highest number of injuries, and the older age group had the higher incidence of blindness. Studies have led to setting more rigid standards, altering rules of the game, and selecting face protectors for hockey players. Older players who care for their equipment prefer the plastic shield face protectors, and the younger players (who complain of fogging and scratching of the plastic) prefer mesh protectors through which neither the stick nor the puck can penetrate. New high sticking (above the shoulder level) rules were included in the 1976 official rule book for Canadian amateur hockey.

Woodpecker drilling behavior. An endorsement of the rotational theory of impact brain injury

High-speed cinematograph films of a drilling woodpecker were examined by direct visual inspection and by a microdensitometer and computer-imaging technique. These showed (1) that the drilling trajectory is essentially linear, with very little, if any, rotation of the head; (2) that there is minimal movement after impact; (3) that the impact velocity is of the order of 600 to 700 cm/s; and (4) that the impact deceleration is of the order of 1,000 g. Dynamic and morphologic findings in the woodpecker may be highly relevant to the prevention of concussion and brain injury in man. Taken in the context of modern packaging technology and other animal and mathematical modelling research, they suggest that brain injury preventive systems could be greatly improved over those now in common use.

Aircrew helmet protection against potential cerebral concussion in low-magnitude impacts

The response of the Gentex DH-151 (contact type) and Gentex 411 (suspension type) aircrew helmets to low-magnitude impacts, such as those sometimes encountered during cockpit buffeting, in ejection, and in parachute landings, was studied to augment the data base on helmet performance. The helmets, mounted on a Hodgson headform, were dropped on the crown and rear at impact velocities up to 4.97 m/s. Acceleration time histories were tape recorded and digitized and Gadd Severity Indices (GSI), among others, were calculated from the resultant acceleration curve. Both helmets kept the GSI below predicted concussion thresholds at 4.97 m/s and were considered to perform well on initial impacts. On second impacts, the GSI rose considerably because the shell and liner of the DH-151 cracked and the suspension of the "141" stretched during the first blow. Improvement of the multiple impact performance of both helmets appears desirable, although the suspension helmet performed slightly better than the contact helmet with respect to the criterion used.

Biodynamic effects of canopy loss in the TF-15 aircraft

In-flight canopy loss in high-speed fighter or trainer aircraft poses serious aeromedical problems for the crew-members. To assess these problems in the TF-15, a series of canopy-off tests were conducted. Preliminary phases of the test consisted of a taxi and a flight test up to 485 knots with pilot in the front seat and an instrumented dummy in the back seat. Upon evaluation of these results, a taxi phase and a flight phase were conducted with a pilot in the front seat and a live subject in the back seat. Maximum air-speed attained was 410 knots. The front crewmember experienced no serious control or medical problems during all phases. The back crewmember did experience problems such as loss of communications, loss of vision, helmet lift, high frequency head buffet, and exhalation difficulties. Airspeed, seat height, and body position had the greatest effect on the severity of the windblast. Angle of bank, angle of attack, and acceleration had little effect. The aft crewmember was able to significantly decrease windblast effects by leaning forward and pulling his head and helmet forward and down with his hand.

National football head and neck injury registry: report on cervical quadriplegia, 1971 to 1975

Data on cervical spine injuries resulting from participation in football have been compiled by a national registry established in 1975. Information has been collected retrospectively by defined criteria since 1971. Efforts have been made to establish the mechanism of injury responsible in the majority of instances on the basis of epidemiologic evidence and recognized biomechanical principles. During the 5-year period, 77 deaths resulted from severe neck injuries. During this period, 1,275,000 players were exposed. Ninety-nine cervical fracture-dislocations resulting in permanent quadriplegia and 259 cervical fractures-dislocations occurred. There may be a "trend" towards an increase in permanent quadriplegia resulting from serious cervical spine injuries sustained while playing football. Apparently, the cause can be attributed to the helmet-face mask that has encouraged the use of the head as the primary point of contact in blocking, tackling, and head butting. The figures clearly identify defensive backs, linebackers, or specialty team members making tackles by using the head as the initial point of contact, as the individuals at greatest risk to sustain cervical spine injuries resulting in permanent quadriplegia.

Developments in the prevention of road injuries

Selected studies of road injury causation since 1960 are reviewed together with corresponding methods of prevention. British road accident deaths have remained relatively low in spite of greatly increased numbers of vehicles. Though not the only factors, improvements in car design and in safety equipment of vehicles have contributed to injury prevention.

Disease prevention and health promotion initiatives: some legal considerations

Public health programs to prevent disease and promote health are constrained by legal doctrines that protect individuals from intrusive regulation of their health-influencing behaviors. This paper outlines the parameters of acceptable interventions in the context of antismoking legislation and motorcycle helmet safety laws. The authors discuss recent court decisions challenging the constitutionality of these laws and identify criteria the courts apply in reviewing governmental attempts to protect the public from disease or trauma.

The operating room and the ultraviolet environment

Clean surgical wounds may be contaminated from three separate sources: endogenously from the patient himself; exogenously from direct contamination by unsterile instruments, drapes, gowns, hands, or gloves; and by bacteria settling from that final common pathway, the air over the operative field. The advent of total joint replacement precipitated a renewed consciousness in the orthopedic community of the disastrous consequences a wound infection can have upon the orthopedic patient. Deep infection around a total joint replacement can convert a procedure with a 95 percent probability of success to a total disaster, leaving the patient worse than prior to operation. Most orthopedists use at least two accepted methods of preventing deep wound infection in the postoperative period: the application of topical antibiotics during surgery, and the intravenous infusion of systemic antibiotics during and after surgery for a brief period. In addition, many orthopedic surgeons are operating in clean air rooms with body exhaust systems; others are operating in an ultraviolet environment. Orthopedic surgery in the ultraviolet environment has been used at the brigham hospitals since 1973. The infection rate has dropped from 3.8 percent to 1.04 percent in a series of 2000 patients. However, inconveniences and hazards have been experienced in the use of ultraviolet radiation in the operating room.

Visual target acquisition and tracking performance using a helmet-mounted sight

Experiments have been conducted on human subjects to assess the efficiency with which a helmet-mounted sighting system can be used to locate and track target sources in the horizontal plane. In the first experimental condition, in which the sight was aligned with discrete stationary target sources, the latency between target presentation and final target location was in the 2-4 s range, dependent upon the amplitude of target offset and the rate of head movement. In the second condition, subjects were instructed to track a sinusoidally oscillating visual image with the sight. Tracking performance was found to be impaired when the frequency of oscillation was increased beyond 0.8-1.0 Hz. Recording of eye movement during both experimental conditions indicated that the impairment of performance could, in part, be attributed to involuntary eye movements consequent upon stimulation of the vestibulo-ocular reflex by the head turning movements.

Go-kart injuries

The pattern and number of injuries which have occurred over a period of 4 years at Aviemore Kart Tract are described. Some of the modifications which have significantly reduced the number and severity of the injuries are discussed.

Nonlinear numerical prediction of human head/helmet crash impact response

A nonlinear, finite-element, model is used to examine the biodynamic impact response to helmeted and unhelmeted headforms having human response characteristics. The human response headform is modeled as a spherical brain of nearly incompressible material, a covering of linear elastic dura, a linear elastic spherical skull, and a layer of nonlinear scalp material. The helmet system is modeled as a partially spherical, highly nonlinear, helmet liner material and a linear elastic fiberglass helmet outer shell. In the case of unhelmeted head impact, the brain pressure response predictions made with the model achieve good qualitative correlation with experiments on impacted human cadaver heads. The model is then used to investigate the response attenuating characteristics of a range of nonresilient helmet liner materials. The results of the study establish the importance of matching surrogate structural compliance and mechanical impedance to that of the human system being simulated if proper assessment of safety system performance is to be achieved.

Eye injuries in Canadian hockey. Phase II

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Retinal detachment following hockey injury

Thirty-three cases of retinal detachment following hockey injury were seen during a 15-year period at the retina clinic of Maisonneuve-Rosemont Hospital, Montreal. Most injuries occurred in adolescents, the average age being 18 years. The mean interval between injury and preoperative examination was 3 years. Almost half of these young hockey players remained legally blind in the affected eye even after a successful operation. A helmet with a protective face visor is suggested as the best prevention against severe ocular damage such as retinal detachment.