Exercise apparatus

#The present invention relates to exercise machines of a type wherein the muscles which move a given part of the body are exercised by separately controlling rotation of the body part about each of at least two mutually perpendicular axes and causing the body part to move against resistance provided by independently adjustable resistance means associated with each axis.

#It is often desirable to exercise the skeletal muscles responsible for supporting and moving various parts of the body in order to strengthen such muscles. Exercise may be undertaken for rehabilitative purposes to restore normal strength and range of motion where muscle tissue has been weakened by disease, injury or prolonged inactivity as commonly occurs when a body part has been immobilized for an extended period in a cast or brace. In otherwise healthy individuals, exercise is beneficial for increasing vigor and maintaining an attractive appearance. For athletes or others engaging in demanding physical activity, exercise improves performance and is believed to reduce the likelihood of injury.

#A skeletal muscle can exert a force effective to move a part of the body only by contracting and shortening in length. Once contracted, force must be applied in order to lengthen the muscle and restore the body part to its initial position. Hence, skeletal muscles are usually arranged around a joint in antagonistic pairs, so that when one muscle contracts, another is lengthened moving the body part in a plane of rotation about a skeletal joint. Most parts of the body, particularly the limbs, are supported and moved by more than a single antagonistic pair of skeletal muscles and are capable of motion in more than one plane. As a consequence, most external body movements can be described in terms of rotational movement about one or more axes of one or more skeletal joints. In the foot for instance, twelve muscles serve to support and move the foot about the ankle. Movement in different directions involves different muscles, some of which are naturally capable of exerting more force than others. This is due to a variety of factors including difference among muscle length and bulk and, significantly, differences in overall mechanical advantage related to the position of the muscle. For example, the muscles responsible for plantarflexion and dorsiflexion of the foot, i.e., moving the foot up and down, are stronger than the muscles which perform inversion and eversion, i.e., rotation of the foot to the inside and outside, respectively. A major shortcoming of exercise machines of the prior art is that they do not adequately accommodate differences in the forces with which a part of the body can be rotated about different axes.

#FIG. 1 is a perspective view showing one preferred embodiment of the apparatus of the invention, used for exercising the foot.

#FIG. 2 is a partial side elevational view of the apparatus of FIG. 1.

#FIG. 3 is a front elevational view taken on line 3--3 of FIG. 2.

#A first preferred embodiment of the invention is illustrated in FIGS. 1 through 5. Referring initially to FIG. 1, the exercise machine 9 of the invention includes a frame 10 fabricated from square steel tubing. Frame 10 comprises a front assembly 11 which extends telescopingly from a rear assembly 12.

#Rear assembly 12 includes a vertical seatpost 15 whose upper end 16 supports a padded seat 17 and whose lower end 18 is welded to the center portion of a rear stabilizer 20. A forwardly extending horizontal female member 22 is welded at its rearward end 25 to rear stabilizer 20 and secured to seatpost 15 by a bracket 26. Female member 22 is supported at its forward end 27 by a short post 28. Female member 22 houses a screw mechanism (which may be of a type known per se and is not shown) for adjusting the extension of front assembly 11 by means of a crank 29 mounted on seatpost 15 opposite the rearward end 25 of female member 22.

#A leg clamp 30 projects forwardly from the underside of seat 17. Leg clamp 30 comprises a padded right jaw 31 and an opposed, padded left jaw 32. Right jaw 31 is mounted to a pivot arm 33 which is connected to an over-center toggle 34 for releasably clamping the user's leg, at or just below the knee, between jaws 31 and 32. In order to accommodate users of different size, the spacing of jaws 31 and 32 can be altered by adjusting the position of left jaw 32 which is slidably secured to underside of seat 17 by a slotted bracket secured to a pair of downwardly protruding bolts by wingnuts (bracket, bolts, and wingnuts not shown).