The benefits of regular exercise have been well established and accepted. However, due to time constraints, inclement weather, and other reasons, many people are prevented from activities such as participating in sports, walking, jogging, running, and swimming. As a result, a variety of exercise equipment has been developed. It is generally desirable to exercise a large number of different muscles so as to provide for balanced physical development, and to achieve optimum levels of exercise. It is further advantageous for exercise equipment to provide smooth and natural motion, thus avoiding significant jarring and strain that can damage both muscles and joints.
While various exercise systems are known in the prior art, these systems suffer from a variety of shortcomings that limit their benefits and/or include unnecessary risks and undesirable features. For example, stationary bicycles are a popular exercise system in the prior art; however, these machines employ a sitting position and require the user's legs to move in a single, fixed, repetitive motion. Cross-country skiing exercise devices are also utilized to simulate the gliding motion of cross-country skiing. While cross-country skiing devices exercise more muscles than stationary bicycles, the substantially flat shuffling foot motion provided by the ski devices limits the range of motion of some of the muscles being exercised.
Treadmills are still a further type of exercise device in the prior art. Treadmills allow natural walking or jogging motions; however, treadmills can enable significant impact loads to be transferred to the hips, knees, ankles, and other joints of the user, particularly when the treadmill is used to simulate running or jogging.
Another type of exercise device simulates stair climbing. Such devices can be composed of foot levers that are pivotally mounted to a frame at their forward ends and have foot-receiving pads at their rearward ends. The user pushes his/her feet down against the foot levers to simulate stair climbing. Resistance to the downward movement of the foot levers is provided by springs, fluid shock absorbers and/or other elements. These devices exercise more muscles than stationary bicycles; however, the rather limited range of up-and-down motion utilized does not exercise the user's leg muscles through a large range of motion. The substantially vertical reciprocating motion of such stair climbing exercise machines can result in substantial impact loads being applied to the hips, knees, ankles and other joints of the user. Further, the up and down reciprocating motion can induce a hyperextension of a user's knee.
A relatively new class of exercise devices is capable of producing elliptical motion that better simulates the natural stride of a person. Elliptical motion is much more natural and analogous to running, jogging, and walking than the linear-type, back and forth motions produced by some prior art exercise equipment. However, these devices that create an elliptical motion are limited to analogizing to running, jogging, and walking motions.
The exercise devices of the prior art largely provide the user with a substantially fixed and limited range of motion that many users' find to be repetitious and uninteresting. It is well known that the more stimulating and enjoyable the experience of exercising is to a user, the longer and more frequently that user will exercise. The very advantage of the exercise equipment described above—the ability to use such equipment conveniently, in a relatively confined space, and in inclement weather—results in exercise devices that are relatively monotonous to use.
Accordingly, a continuing need exists for an exercise device that provides an enjoyable stimulating experience and avoids being relatively monotonous to use. A need exists for an exercise device that enables a user to use his or her own creativity to define the exercise movements. There is also a need for an exercise device that enables the user to exercise muscles in a smooth natural manner, without applying undesirable impact loads to the user's joints. There is also a need for an exercise device that enables a user to improve his or her stability, coordination, rhythm and balance. It would be desirable for such an exercise device to be configured for convenient use in a relatively confined space even in inclement weather.