The Pedestrian's Record

THE PEDESTRIAN'S RECORD. 2 1 5 though notof great latitude,possess great force, and ensure the fixity of the toes to the ground, thusaffording that pedal grasp which gives security to the foot-fall and velocity tothe runner. THE POSTERIOR FORMATION OF THE LEG Consists of agroupof musclessituated on thehinderpart of the leg, which are antagonistic in their actionto those on the fore. The extensormagnus isa large muscle, andconstitutes the calf of the leg, and is able to elevate the heel, and with it the whole weight of the body. At its lower extremity it forms a single tendon—thetendoAchillis—which is attached to the heel. Rupture of this tendon sometimes occurs, as explained at page 7. The gastrocnemus consists of two parts, an outer and an inner, both situated at the back part of the leg. It arises by two heads from the outer and innercondyle offemur or thigh­ bone, spreads over the inner and outer, and, as it were, bifurcates one portion to the rightand theother tothe left, to again join lower down in a tendon commonto both, whichalso unites with one from the soleus, and together assist in the formation of the tendo Achillis. The soleus is situated beneath the foregoing muscle, and shorter than it, and descends lower down before forming the common tendon. It arises from the head of the fibula, and passes down the leg tojoin with the gastrocnemus in forming the largest tendon in the human body, namely, the tendo Achillis, whichisabout six inches in length,and is inserted intothe lower part ofthe os calcis, or heel-bone. The actionof these muscles is considerable, and their full developmentandpowerisexerted instandingand w lking, and are brought intoextensive recjuisition during running and the act of leaping. It is upon these muscles that the baneful effects of excessive strainis likely to occur, such as partial laceration of muscular and tendinous tissue, or even rupture of the great tendon Achillis.