To compare hiking stick use on lateral stability while balancing with or without a load (15-kg internal frame backpack) under conditions of no stick, 1 stick, and 2 sticks for six trials 15 volunteers ages 19 to 23 years (M = 21.7 yr.) were tested six separate times on a stability platform. During randomly ordered, 1-min. trials, the length of time (sec.) the subject maintained balance (+/-10 degrees of horizontal) and the number of deviations beyond 10 degrees were recorded simultaneously. Backpack and hiking sticks were individually adjusted for each subject. A 2 x 3 repeated factor analysis of variance indicated that subjects balanced significantly longer both with and without a load while using 2 hiking sticks than 1 or 0 sticks. Significantly fewer deviations beyond 10 degrees were found when subjects were without a load and using 1 or 2 sticks versus when they used none, and no significant difference in the number of deviations were found between 1 and 2 hiking sticks. When subjects were equipped with a load, significantly improved balance was found only between the 2 sticks and no sticks. Balance was significantly enhanced by using hiking sticks, and two sticks were more effective than one while carrying a load. An increase in maintenance of static balance may reduce the possibility of falling and injury while standing on loose alpine terrain.

The indiscriminate use of caffeine by people of all ages may present health hazards. The public at large needs to be more informed of the presence of caffeine in commonly consumed foods and beverages, particularly by infants, children and pregnant women. It is the responsibility of all consumers to investigate the caffeine content of suspected products so that intake may be objectively monitored. Although doubts still exist about the efficacy of caffeine as an ergogenic aid, particularly for exercise of high intensity and short duration, the IOC and the National Collegiate Athletic Association of the US have adopted bans on the use of caffeine to aid sport performance. Currently, both of these organizations prohibit the concentration of caffeine in urine to exceed 15 micrograms-ml-1. That is to say, only very large amounts of caffeine are not permitted at present. Additional research is needed to confirm or deny the contraindications presented by the ingestion of caffeine on a chronic basis.

No abstract

Students' current use of backpacks to carry heavy loads of school material has promoted concern about musculoskeletal discomfort and postural problems. The purpose of this study was (a) to compare ratings of perceived comfort between subjects' personal backpacks and an experimental backpack and (b) to compare the data from two comfort rating scales. College-aged students (N= 19) in a random ordered, cross-over design rated their personal, traditional backpacks and experimental backpacks for perceived neck, shoulder, back, and overall comfort on a 100-mm Visual Analog Scale and on an Anatomical Illustration Rating Scale. Analysis indicated no significant difference in comfort ratings of backpacks on Visual Analog Scale but, on the Anatomical Illustration Rating Scale the experimental backpack was significantly (p<.05) more comfortable for the back. Further comparisons of backpacks, based on median splits of subjects' weight, height, and body mass index, indicated that body size is related to comfort ratings of backpacks. Special features of the experimental backpack may have contributed to greater comfort in selected areas based on body proportion. Subjective rating systems are not equally sensitive in distinguishing comfort. While backpacks with unique features may improve comfort, manufacturers should consider the size of the users in developing backpack designs.

Until recently, resistive training for prepubescents has met largely with skepticism. Original, and possibly premature, conclusions with respect to the efficacy of weight training on prepubescents, considered insufficient circulating androgens in children as the predominant restriction to strength gains. Additionally, safety concerns regarding bone integrity, epiphyseal continuity and risk of injury have been common. A review of the most recent investigations overwhelmingly supports significant strength gains in prepubescents as a result of weight training. Further, based on recent findings of short-term prepubertal weight training, no damage to bone, epiphyses, growth tissue, or muscle has been reported. In light of these findings, weight training may be recommended provided expert professionals are consulted and strict supervision is maintained. It is also recommended that repetitions be maintained within the 6-10 range rather than utilizing maximum weight. J Orthop Sports Phys Ther 1989;11(3):96-99.