The purpose of the present investigation was to study muscle strength in adolescents and its relationship t o serum levels of testosterone and growth hormone in both genders.Thirty active adolescents (15 boys; age range 11 -12 y/o) participated in the first study. lsokinetic muscle strength of the dominant knee extensors (KE) was determined at 0,12.20.30. 120,180 and 240 deglsec using a Cybex 340 dynamometer. The assessment of pubertal status was accomplished using the criteria of Tanner. Serum levels of total testosterone (T) and growth hormone (GH) were determined using radioimmunoassay techniques. Boys had higher (p < 0.001) T levels but no differences in muscle strength were detected between genders. Fifty-seven additional subjects representing three age groups (11 -12 y/o, n -18; 13-14, n=21; 17-18, n=18) participated in the second study. A significant increase in peak torque (absolute and corrected for body weight) with age was observed in both genders. There were no significant gender differences in strength for the two youngest age groups, but boys were stronger than girls in the oldest age group (group 3). Testosterone and GH levels increased with age in boys but not in girls. Gender related differences in T were found in groups 2 and 3. A positive correlation (r = 0,64 boys; r = 0.46 girls) between testosterone levels and absolute muscle strength was seen in both genders. Our results suggest that increases in anabolic hormones precede muscte strength gains in adolescent males. In addition. gender related differences in muscle strength during adolescents cannot be explained solely on the basis of difference in body sire or T levels.

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Objective. To study if Randomized Controlled Trials (RCTs) in rehabilitation (a field where complex interventions prevail) published in main journals include all the details needed to replicate the intervention in clinical practice (clinical replicability).Study Design and Setting. Forty-seven rehabilitation clinicians of 5 professions from 7 teams (Belgium,

PURPOSE: The objective of this paper is to present a case series of patients with diagnosis of torticollis due to Grisel's syndrome and, in doing so, raise awareness of an unusual condition that could be fatal. A review of the literature is presented regarding diagnosis and treatment. METHODS: Case series of three patients that were 7, 10, and 12 years old with history of tonsillitis or neck surgery consulted to the service of Rehabilitation Medicine. RESULTS: Physical examination showed a fixed head or limitation of movement to neutral position and initially a normal neurological examination. Initial cervical X-rays were not diagnostic. The final diagnosis was made by CT scan or MRI. All 3 patients were treated with anti-inflammatory medications, immobilization, and/or cervical traction or surgery. CONCLUSION: Grisel's syndrome is a non-traumatic atlanto-axial rotatory fixation (AARF) with or without subluxation following infection or surgery in the head or neck region. This paper presents an unusual cause of torticollis that could be fatal or cause neurological injury if not recognized and treated appropriately.

Objective To determine the anaerobic power and muscle strength of preadolescents with human immunodeficiency virus (HIV). Design Cross-sectional design. Setting Human performance laboratory at the University District Hospital at the Puerto Rico Medical Center. Participants Fifteen preadolescents (8 girls and 7 boys) with a classification of HIV A and B attending an investigational treatment program at the University Pediatric Hospital. Fifteen seronegative control subjects matched by age and gender also were included. Main Outcome Measures The power of the lower extremities was measured with use of the Wingate Anaerobic Power Test on a MONARK cycle ergometer (mean power in watts). Local muscle strength of the dominant knee extensors (peak torque/body weight × 100) was tested with an isokinetic dynamometer set at 60 deg/s. Statistical analysis was performed with the Wilcoxon signed-rank test, and statistical significance was accepted at an α level of <.05. Results No significant differences between the control group and study group were detected on muscle strength testing. The study group presented a lower anaerobic power (mean power) compared with control subjects (P = .04). Conclusions This exploratory study suggests that HIV-infected preadolescents present lower anaerobic power compared with uninfected control subjects. Our findings of impaired anaerobic capacity can have clinical implications in this population because most of the activities of daily living, such as play, leisure, and sport activities, are short term and high intensity (anaerobic) in nature.