Phasic Activity of Intrinsic Muscles of the Foot t

An electi-omyogi-aphic study was done of the phasic activity of six intrinsic muscles of the foot: the extensor digitorum brevis, abductor hallucis, flexot- hallucis bi-evis, flexot- digitoi-um bi-evis, abductor digiti minimi, and the dorsal intei’osseus muscle between the third and fourth toe. Experimental conditions were: walking on level gi-ound, up and down a 10-degree slope, and up and down stairs; standing on toes; and quiet standing. Sites of eliot 1o(l( ’ I)Ia(-enwnt:.1, aI nlw-tor digiti minirm B, eXt (11501 (ligit oritns 1 irevis: ( ‘, iiiursa 1 mit (‘ti)55(’tis: 1), tI)(Iti(tOI Irailtu-is; E, flexor digitorum brevis; I”, flexor lIallu(-is 1 revis. Methods Twelve subjects whose ages i-anged fi-om fifteen to twenty-five yeats pat-tici-pated. None had aisy gioss abisoi-malities which could pi-oduce aix altet-ed walking pattet-it. 1’acls foot was cai’efully examined and the clsaractei-istics of the at-eli were recoi’ded. The i-ight foot was studied in all cases. ‘I’hie skiii over the site fot elect i-ode placement was cleaned and a one-centimeter subcutaneous lidocaine wheal was pi-oduced through which the stet-ilized electrodes were placed (1”ig. 1). F;lecti-odes coissisted of 36-gauge, enamel-coated, stainless-steel wire. The electi-ode was pi’epared by cleaning its tip of enamel, sti-inging it tlii-oiigls a 26-gauge * ()nn ’ of tIl( ’ four \ernon P. ‘Fltompsun Resident-framnitsg Program awarul-wintnimnig l)aI)ers