Effects of fatigue on knee proprioception.

OBJECTIVE: To investigate the effects of muscular fatigue on knee joint proprioception. DESIGN: Prospective study. SETTING: Exercise physiology laboratory. PARTICIPANTS: Sixteen (eight men and eight women) healthy volunteers ages 19-27 years, with no history of neuromuscular disorders, vestibular disorders, or lower limb injuries (e.g., ligament/meniscus tear). INTERVENTION: Three separate fatigue protocols [ramp test (RT), continuous test (CT), and interval test (IT)] were performed. All tests consisted of lower limb cycling on a computer-driven cycle ergometer (Lode). The RT was used to calculate the maximal aerobic power (VO2max) and determine the work rates for the CT and IT. Work rate for the RT increased 20/25 W/min to maximal exhaustion. The CT consisted of cycling at 80% VO2max until maximal exhaustion. The IT consisted of cycling alternately at 120% VO2max and at 40% VO2max for 30 s each to the point of maximal exhaustion. MAIN OUTCOME MEASURE: In the standing position, subjects were instructed to perform a two-legged squat to specific knee flexion angles. The absolute angular error (AAE) was measured for each test angle using an electrogoniometer (Penny & Giles, Blackwood, Gwent, U.K.) placed laterally across the dominant knee joint. AAE was defined as the absolute difference between test angle and subject perceived angle of knee flexion. RESULTS: A statistically significant increase in AAE after the RT (1.0 +/- 0.66 degree, p < 0.01), CT (0.70 +/- 0.66 degree, p < 0.03), and IT (1.24 +/- 0.79 degrees, p < 0.01) protocols was observed in the male subjects. Female subjects reported a statistically significant increase in AAE after the CT (0.73 +/- 0.73 degree, p < 0.03) and IT (1.1 +/- 0.89 degrees, p < 0.01) protocols and a nonsignificant increase in AAE (0.19 +/- 0.70 degree, p > 0.5) after the RT protocol. CONCLUSION: These findings suggest that exercising to fatigue may produce a change in subjects' reproduction ability of knee joint angles. This may represent a decline in proprioceptive function after heavy exercise bouts. Whether this suggested proprioceptive decline is at the clinical significance level (e.g., significantly altering joint stability and motion) cannot be determined from the present findings.

Checking from behind in ice hockey: a study of injury and penalty data in the Ontario University Athletic Association Hockey League.

OBJECTIVE: In this study we investigated the association between the introduction of the checking-from-behind rule (CFB) in the Ontario University Athletic Association (OUAA) hockey league and player safety. DESIGN: Injury and penalty data were collected for the 3 years prior to and the 3 years following the introduction of the CFB rule in 1989. PARTICIPANTS: There were 653 injury records and 389 penalty records for 3 OUAA teams that had complete records for the 6 years. MAIN OUTCOME MEASURE: In the absence of any a priori evidence, the null hypotheses of no association between the CFB rule and injuries or penalties, apart from a logical assumption that there would be a pre-/post difference in CFB penalties, were tested. RESULTS: Although the injury rates for each of the body segments (heat/neck, back, shoulder) demonstrated a significant independence (chi 2 = 56.66, df = 2, p < 0.001) from each other in relation to the pre-/post rule period, only the CFB penalty rates exhibited significant independence (chi 2 = 16.58, df = 2, p < 0.001) from body contact and stick-related penalties. CONCLUSIONS: These findings suggest that the introduction of the CFB rule was related to a safer playing environment as reflected by a pre-/post rule decrease in two of three categories of injury, increased CFB penalty rates, and the absence of significant association between the CFB rule and the decreases in body contact penalties and stick-related infractions. It appears that the medical community, with the supporting clinical data demonstrating CFB-related injuries, has helped create enhanced safety without significantly changing player behavior.

Hockey injuries.

Hockey, Canada's national sport, is probably the world's fastest team sport. The nature of the game makes injuries a common occurence. This article reviews the literature on hockey injuries and identifies some of the changing trends over the past 15 years. Severity and incidence of injuries increase with the age and skill level of the player. There are fewer lacerations, eye injuries, and head injuries since helmets and facial protectors have become mandatory in minor hockey. However, there has been an increase in spinal cord injuries. Physicians who provide medical coverage for older adolescent and adult competitive élite hockey players should be proficient at assessment and acute care of patients with life-threatening injuries.

Frequency of the branchio-oto-renal (BOR) syndrome in children with profound hearing loss.

Nineteen of 421 white children in Montreal schools for the deaf had preauricular pits. The branchio-oto-renal (BOR syndrome was identified in four of the nine families who agreed to family investigation, including audiograms and intravenous pyelograms (IVPs) and may have been present in several others. The penetrance of this autosomal dominant syndrome appears to be high. It is estimated that severe renal dysplasia occurs in about 6% of heterozygotes. The presence of a preauricular pit at birth suggests that the child has at least one chance in 200 of severe hearing loss, and this warrants a careful family history, as well as alertness for any signs of hearing impairment. Offspring of affected individuals are eligible for parental diagnosis of renal dysplasia.