RESUMEN
A parametric investigation of the thoracic injury potential of basic taekwondo kicks was conducted through the use of computer simulations. Linkage-based models were employed to simulate the kinetics of the kicking leg and were used to drive a human thorax model. The results of the analysis according to the thoracic compression criterion indicated a minimal probability of severe injury (AIS4+) for swing kicks, nearly 0 percent and thrust kicks, less than three percent. The thoracic viscous criteria, on the other hand, predicted a severe injury probability of up to 100 percent for swing kicks and up to 80 percent for thrust kicks. Additional analysis showed that the injury potential was a strong function of the kick velocity and a weak function of the applied constant force. The injury potential was also found to be a weak function of the size and weight of the kicking leg, with variations in the peak compression and viscous response being typically below 5 percent for a 20 percent change in either the mass or the length.
Asunto(s)
Simulación por Computador , Artes Marciales/lesiones , Modelos Anatómicos , Traumatismos Torácicos/fisiopatología , Fenómenos Biomecánicos , Estudios de Evaluación como Asunto , Humanos , Puntaje de Gravedad del Traumatismo , Cinética , Traumatismos Torácicos/etiología , ViscosidadRESUMEN
BACKGROUND: The safety of psoralen plus ultraviolet A (PUVA) light therapy has been an issue of debate. A few multiple-center cooperative studies have reported an increase of basal cell and squamous cell carcinomas among PUVA-treated patients. In our institute, more than 1000 patients have been treated with PUVA since 1975. OBJECTIVE: We investigated the incidence of skin cancer among patients who received high doses of PUVA to see whether such incidence increased. METHODS: This is a historical cohort study of two comparison groups of patients. Subjects under study were 492 psoriasis patients who received PUVA treatments between 1975 and 1989. One group of 103 patients, defined as the high-dose group, received an accumulated PUVA dose of 1000 joules/cm2 or more; another group of 389 patients, as the low-dose group, received 200 joules/cm2 or less. The occurrence of skin cancer in the two comparison groups is analyzed. RESULTS: In the high-dose group we observed an increased number of patients with squamous cell carcinoma, keratoacanthoma, and actinic keratosis. We did not see any patients with genital cancer, melanoma, or an increased number of patients with basal cell carcinoma. CONCLUSION: The risk of squamous cell carcinoma developing in patients who received a high dose of PUVA is confirmed. We speculate a combination of factors, including PUVA, may contribute to this risk.
Asunto(s)
Carcinoma Basocelular/inducido químicamente , Carcinoma de Células Escamosas/inducido químicamente , Terapia PUVA/efectos adversos , Psoriasis/tratamiento farmacológico , Neoplasias Cutáneas/inducido químicamente , Adulto , Carcinoma Basocelular/epidemiología , Carcinoma de Células Escamosas/epidemiología , Estudios de Cohortes , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Queratosis/inducido químicamente , Masculino , Persona de Mediana Edad , Neoplasias Cutáneas/epidemiología , Factores de TiempoRESUMEN
One hundred four psoriatic patients who had 8-methoxypsoralen-ultraviolet light A (PUVA) treatment between 1975-1987 were investigated to determine if skin cancer had ever occurred during or after the therapeutic period. Incidence data of skin cancer was applied to this group of patients to measure the expected number of patients with skin cancer. The significance of observed number versus expected of PUVA-treated patients with skin cancer was analyzed. The authors did not observe a significant increase of patients with skin cancer.