Hops and Walking

HOPS, Humulus Lupulus L., a perennial herbaceous climbing plant of the hemp family (Cannabineae), cultivated throughout Europe, in North America, Brazil, and Australia, and in our country in the Caucasus, the Ukrainian SSR, the Byelorussian SSR, as well as in Siberia. In medicine, the infructescences (cones) and the glands obtained from them, called hop flour or lupulin, were used. They were credited with restoring the normal activity of weakened male sexual organs and eliminating nervous insomnia and painful erections. At the present time, both preparations have been almost abandoned by medicine. In folk medicine, hops are used as a stomachic and for scrofula in the form of emollient poultices. In veterinary medicine, it is used as a bitter agent to stimulate appetite. Hops have great industrial importance in brewing. Hops are an export item.

WALKING. An element of walking is the so-called double step, during which each leg alternately becomes the supporting and swinging leg, and by the end of which all segments of the walker's body return to their initial position. According to data from O. Fischer and W. Braune on three subjects, the swing period lasts 0.415 seconds and ends with the heel of the swinging leg touching the ground. The subsequent double-support period lasts 0.081 seconds. At the end of this period, the other leg, which was previously the supporting leg, lifts off the ground with the toe and becomes the swinging leg, while the one that was previously swinging becomes the supporting leg; this single-support period lasts 0.577 seconds. Its end coincides with the contact of the swinging leg with the ground, after which the last phase of the step occurs—the second double-support period. Walking is a collection of cycles—double steps. In running—this is its difference from walking—there is no double-support period, and furthermore, both legs are in the air simultaneously. During walking, the center of gravity of the entire body experiences transverse and, what is especially important, vertical oscillations. The amplitude of the latter is about 4 cm. These oscillations are of interest in that the work performed during walking is calculated from them, and they partly determine the changes in the pressure of the feet on the surface. The movements of the arms during walking are an echo of the movements of the forelimbs of human ancestors, who moved using four legs. Now these movements balance the oppositely directed swings of the hip line and the lower part of the torso. During walking, the extensor muscles of the legs (mm. glutaei max., mm. quadricipites femoris et mm. tricipites surae) take the greatest part. The pressure of the foot on the surface over which walking is performed has two maxima (the pushing off of the swinging leg from the ground—the 'rear thrust'—and the placement of the heel on the ground at the end of the swing—the 'front thrust'). For a person weighing 70 kg, the vertical component of the pressure on the ground ranges from 90 to 100 kg. This value determines the possibility of a person walking on soft ground, flooring, or footbridges. With loaded walking, both the kinematics and dynamics of walking change. According to data from T. S. Popova, in a person walking with a load, the double-support period is lengthened at the expense of the swing and single-support periods. The vertical oscillations of the center of gravity increase almost twofold. Steps are shortened. The speed of normal walking ranges from 3 to 5 km per hour. The number of steps (single) is about 120 per minute. In different armies, various standards for marching (see) are adopted. Energy expenditure at 114 steps per minute is equal to 48 small calories per 1 meter; with a full combat load of 29 kg, it is equal to 61 small calories per 1 meter. Walking is one of the most stable secondary automatisms created in early childhood. This explains the enormous stereotypy of walking cycles, which differ from one another by an insignificant amount. Thanks to such stereotypy, it is possible to deeply study the mechanism of walking using one typical step. Walking, as one of the most important human movements, has long attracted the attention of researchers; mechanical (Amar), photographic (Muybridge, Braune and Fischer, Bernstein), and cinematographic methods of studying walking have been proposed. The most accurate method is the cyclogrammetric method, developed in detail by N. Bernstein (see Cyclography).