effect of shoe sole tread groove depth on the gait parameters during walking on dry and slippery surface

Prevention of slipping accidents requires provision of adequate friction through the use of suitable combinations of footwear and underfoot surfaces. Shoe sole tread groove is one of the important factors on friction coefficient during walking. To measure the effect of different shoe sole tread groove depths and different surfaces on the required quotient of friction [Q], heel strike velocity and occurrence time of ground reaction forces [GRF] in stance phase during walking on slippery and dry surfaces. In this semi-experimental study, 22 healthy men were studied under different conditions. The studied independent variables were shoe groove depths [included 1, 2.5 and 5 mm] and type of walking surface [dry and slippery]. Biomechanical gait analysis was carried out with 396 single steps. Data were collected by motion analysis system and two force platform. The occurrence time of GRF was significantly faster on dry surface than slippery surface [p<0.01]. Q was significantly lower on slippery surface and with groove depths of 1 and 2.5 mm. The highest value of Q was observed with the deepest groove depth of 5 mm. Heel strike velocity did not differ significantly in the 6 conditions tested. Tread groove depth is a significant factor affecting the Q at the shoes-surface interface on dry and slippery floors. It seems that deeper groove is more appropriate for maintaining the stability during walking. The walking surface affects the occurrence time of GRF; the force components occur sooner on the dry than slippery surface

Catamenial anaphylaxis

It is well documented that the hormonal changes during menstrual cycle influences systemic diseases, among them are allergic disorders. There are some reports of cyclic anaphylactic reactions during menstrual period which is reffered as [Catamenial anaphylaxis]. It must be differentiated from a closely related condition called [APD] or autoimmune progesterone dermatitis which is also a rare condition. It seems that hormonal changes especially rising progesterne levels and other mechanisms like back-diffusion of prostaglandines from contracting uterus into the systemic circulation may have some role in pathogenesis of these conditions. In catamenial anaphylaxis symptoms appear in direct association with the start of the menstrual flow but in APD, sign and symptoms begin earlier in the pre-menstrual phase. A 19 year old girl [not married] was referred because of a 8-months history of recurrent monthly urticarial and anaphlactoid reactions. Her symptoms began at first day of menstruation and lasted 1 to 2 days. The eruptions started as a sense of flushing and intense pruritis all over the body. Soon urticarial lesion as giant hives appeared which in some instances was associated with respiratory distress. The patient denied any changes in her diet and had taken no medications. Complete blood Count and erythrocyte sedimentation rate [ESR] revealed no abnormalities but VDRL positivity led us to consider rheumatological background like systemic lupus erythematosous. Anti cardio Lipin antibody [ACLA] was surprisingly above normal laboratory values. Her serum was taken in an episode of cyclic anaphylactic reactions and stored to be used later in her cycle when no more menstruating. Skin prick test with autologous serum collected during menstruation is performed at the midcycle and also in the late-cycle period in another ovulatory cycle. Both prick tests led to resurgence of severe allergic reactions as flushing, urticaria, pruritis and dry cough which were managed appropriately. The patient's history and physical examination and hormonal assay were consistent with catamenial anaphylaxis. She is currently under control and follow up, using cyclic conjugated estrogens