The Effect of Ballet Shoes on Plantar Foot during Ambulation

OBJECTIVE: The purpose of this study is to measure plantar foot pressure and to make comparison of plantar foot pressure between measurements with and without ballet shoes. METHOD: Sixty six feet of healthy ballerinas were evaluated by Footscan plate and Foot scan Pro 4.5 program to analyze plantar foot pressure. We measured plantar foot pressure with and without ballet shoes respectively. The foot was divided into 7 different points on the basis of each metatarsal bone head, 1st toe, and heel. Also total plantar foot pressure was measured. RESULTS: There were no difference in plantar foot pressure between with and without ballet shoes. The highest pressure point of plantar foot in all subjects is the heel with ballet shoes and the great toe without ballet shoes. And the highest pressure point of plantar foot in skilled ballerinas is the great toe with and without ballet shoes. Also the highest pressure point of plantar foot in unskilled ballerinas is the heel with ballet shoes and the second metatarsal head without ballet shoes. CONCLUSION: We concluded that the ballerinas may need the protective ballet shoes.

Impaired Metabolic Signal Transduction Networks in Isolated Skeletal Muscle in Korean type 2 Diabetic Patients / 대한내분비학회지

BACKGROUND: The glucose uptake rate is the limiting step in glucose utilization and storage. The failure of insulin to stimulate glucose uptake in muscle appears to be a primary defect of insulin resistance. This study was undertaken to examine the effect of physiological hyperinsulinemia on the phosphorylation of the insulin receptor (IR-beta), insulin receptor substrate (IRS), Akt kinase and GSK-3 in isolated skeletal muscle, in people with type 2 diabetes (n=9) and control subjects (n=11). METHODS: 75g OGTT and euglycemic hyperinsulinemic clamp test were done. And vastus lateralis muscle was obtained before and 30 min into the euglycemic clamp. Western blots were performed for tyrosine phosphorylation of insulin receptor substrate (IRS) and phosphorylation of the insulin receptor(IR-beta), Akt and GSK-3. RESULT: There were no statistical differences in the mean age, BMI and body fat between the control subjects and diabetic patients. The fasting blood sugar and HbA1c in controls and diabetic patients were 98.+/-1.3 and 208.1+/-16.5 ng/dl, and 5.4+/-0.5 and 9.2+/-0.6%, and 1.4+/-0.2 in the control subjects, and 72.2+/-52.3% (p<0.01) and 10.2+/-6.3 (p<0.01) in the diabetic patients, respectively. The insulin resistance from the euglycemic hyperinsulinemic clamp tests were 8.2+/-0.6 mg/kg/min and 3.7+/-1.1 ng/kg/min in the control subjects and in the diabetic patients, respectively (p<0.01). Compared with the normal controls, insulin-stimulated IR phosphorylation was no different to that in the diabetic patients. However, insulin-stimulated IRS phosphorylation, insulin-stimulated Akt phosphorylation and insulin-stimulated GSK-3 phosphorylation were reduced in the diabetic patients compared with the normal controls by 24, 43 and 25%, respectively (p<0.05). CONCLUSION: In korean type 2 diabetic patients, the insulin resistance may be due to the impairment of the upstream insulin signal molecular network. Further studies will focus on determining whether these signaling defects are the cause of the development of insulin resistance, or secondary to the altered metabolic state, associated with type 2 diabetes mellitus

Analysis of Six Positions in Ballet by Measurement of Foot Plantar Pressure

OBJECTIVE: The purpose of this study is to analyze the distribution of plantar pressure in six balletpositions and to compare those between the skilled and unskilled ballet dancers. METHODS: Thirty eight feet of healthy ballerina were evaluated by EMED-SF (Novel GMBH Inc. Ger.) system to analyze six positions of ballet. At each position, we estimated the static and dynamic positions. The forefoot was divided into 6 different zones on the basis of head of metatarsal bones. The degree of discipline was assessed by 3 expert ballerina. RESULTS: In each position, there were significant peak pressure distribution areas. In the skilled ballerina, there was less difference in peak pressure between the static and dynamic positions in comparision with the unskilled ballerina. In the skilled ballerina, more forces are distributed to M6 area in releve position and to M3 and M6 areas in turnout positions. CONCLUSION: Six basic ballet positions could be analyzed by plantar pressure measurement. There were some differences in the distribution of planter pressure in some ballet positions between the skilled and unskilled ballet dancers.