Assessing Knee Stability in Adolescent Athletes with Osgood-Schlatter Disease Using the Y-Balance Test.

PURPOSE OF THE STUDY Osgood-Schlatter disease develops secondary to chronic patellar tendon overloading. The present study was designed to determine whether athletes with Osgood-Schlatter disease perform significantly worse in the Y-Balance Test compared to healthy subjects in a control group. MATERIAL AND METHODS The study involved ten boys (average age 13.7 years). Seven participants had bilateral knee pain, swelling and tenderness whereas three had unilateral knee pain, swelling and tenderness (left knee in two cases, and right knee in one). Overall, 17 knees were assessed (left knee in nine cases and right knee in eight).Ten healthy adolescent professional football players (mean age 14.6 years) were selected as a control group. In both groups, complex knee stability was assessed using the Y-Balance Test and their data were analyzed using the methodology developed by Plisky et al. The test outcome was expressed in indexed (normalized) values for the right and left lower extremities, and averaged values for the individual directions were compared. RESULTS Significant differences between both groups were shown in the posteromedial and posterolateral directions. CONCLUSIONS Using the Y-Balance Test, our study documented reduced performance in the above directions in patients with OsgoodSchlatter disease. Key words: Osgood-Schlatter disease, knee, balance test, movement patterns patellar tendon overload.

Exercise Tolerance in Patients With Idiopathic Pulmonary Fibrosis, Effect of Supplemental Oxy-Gen.

Exercise tolerance in patients with idiopathic pulmonary fibrosis IPF is mainly limited by mechanical constrain of ventilation and high physiologic dead space. Oxygen enriched gas inhalation seems to increase ventilatory efficiency by reduction of dead space to tidal volume ratio (VD/VT) which probably mirrors improved pulmonary capillary flow and leads to longer physical tolerance at lower level of minute ventilation. The effect is noticeable at FIO2 that can be delivered in rehabilitation purposes or daily living activities.

Effect of the early postnatal administration of cortisol on development of the nervous control of cardiac function in albino rats.

When infant rats were treated with cortisol, in daily s.c. doses of 20 mg X kg-1, between the ages of 2 and 15 days, the noradrenaline content of their heart and spleen, between the ages of 23 and 65 days, was lower than in the controls. The decrease in the noradrenaline content did not diminish with advancing age; on the contrary, it was the most pronounced at 65 days. Cortisol treatment did not affect the noradrenaline content of skeletal muscles. The functional significance of the decrease in the noradrenaline content was studied in nervous control of the sinoatrial node of the heart. In agreement with the drop in noradrenaline concentration, transmural stimulation of the sinoatrial node region of isolated atria led to a mild, but statistically significant reduction of the function of sympathetic nerve endings, whereas parasympathetic innervation of the node showed no signs of impairment. This peripheral functional deficiency of sympathetic innervation of the node is not seen in the intact organism, where it is masked by central nervous mechanisms. Rats given cortisol postnatally had a significantly higher heart rate at 23, 33 and 44 days, because, in the presence of normal sympathetic influence, the tone of the parasympathetic nerves was reduced. The heart rate was highest at 23 days; with advancing age the difference diminished and at 65 days it was statistically nonsignificant.

Effect of repeated exercise on postnatal development of the noradrenaline content of the albino rat heart, spleen and skeletal muscle.

The authors studied the effect of repeated elevation of sympathetic activity on the postnatal development of the noradrenaline content of tissues of the albino rat. Between the ages of 15 and 29 days, young rats were forced to swim in water heated to 25 degrees C, 3 X 30 min on weekdays and 1 X 30 min on Saturdays and Sundays. At 30, 45 and 65 days, the noradrenaline content of the tissues was determined spectrofluorometricaLly by the trihydroxyindole method. The noradrenaline content of the heart of trained rats was higher than in the controls in all the given age groups and the size of the absolute difference rose with advancing age. The noradrenaline content of the spleen developed similarly. Repeated exercise did not lead to an increase in the noradrenaline content of skeletal muscle. The results show that the repeated elevation of the activity of sympathetic adrenergic neurones which occurs in young rats during exercise is a long-term factor stimulating the development of sympathetic innervation of the heart and spleen. The development of the neurones innervating skeletal muscle was not stimulated, probably because the activity of these neurones is not increased by stress.

Dependence of the cytotoxic effect of guanethidine on the degree of sympathetic activity.

Young rats aged 15-29 days received a subcutaneous injection of guanethidine sulphate (5 mg/kg body weight) every day. Owing to damage to the postganglionic sympathetic neurones, on about the 60th day of life we observed a significant decrease in the noradrenaline concentration in these animals' hearts compared with the controls. If every guanethidine injection was followed immediately by intensive physical exercise, there was no drop in the heart noradrenaline concentration. Physical exercise of the same intensity performed a few hours before injecting guanethidine did not prevent the drop in the noradrenaline concentration in the heart. The results show that an exercise-induced increase in sympathetic activity, at a time when guanethidine is circulating in the blood and accumulating in the adrenergic neurones, inhibits the cytotoxic effect of guanethidine. Isolated physical exercise performed between the 15th and 29th day of life leads to an increase in the noradrenaline content of the heart of rats aged 60 days.