Abdominal muscles are used in all human motions, including breathing, sitting and standing. Strong abdominal muscles are crucial for torso stability, good posture and the avoidance of back problems. The primary abdominal muscle, erectus abdominous, controls the tilt of the pelvis and the consequent curvature of the lower spine. Other abdominal muscles reach around the back and play an important role in posture and back support. Several muscles have fibers aligned in different directions. For example, the internal and external obliques have anterior fibers that run vertically between the ribs and the pelvis. Due to the different directions in which such muscles are aligned, development and toning of such muscles is preferably attained by movement in more than one direction movement pattern. The transverse abdominous muscle is the chief muscle of forced expiration. Along with the erectus abdominous and external and internal obliques, the transverse abdominous is involved in holding the abdomen flat.
To properly condition the abdominal muscles, it is necessary that an exercise target the abdominals specifically and involve movements directly caused by the abdominal muscles. To attain desired conditioning, the abdominals must also be overloaded to force them to do more than they are typically accustomed to do. Finally, the abdominal muscles should be worked from a variety of angles to accomplish maximum muscle fiber involvement in muscle contraction.
A variety of conventional abdominal exercises have been touted as being effective. Straight-leg sit-ups, Roman chair sit-ups, pivoting seated apparatus and pre-formed plastic rocking devices are but a few of the multitude of exercise devices and machines used by individuals to firm and tone abdominal muscles. Because the abdominals have a substantially narrow range of motion, the above-referenced exercises and devices work muscles other than the abdominals, thus reducing the efficiency of the desired abdominal workout. Indeed, movement beyond an approximately 30 degree range must necessarily involve muscles other than the abdominals. In many of the abdominal exercise devices available today, the psoas magnus and psoas parvus muscles, which run down the front of the legs, up through the pelvis and attach to the lowest six spinal vertebrae, are contracted. These muscles pull a person's torso toward their legs and have a significant range of motion, flexing a person forward all of the way from a full back bend and back until a person's chest touches his/her knees. The psoas muscles compete with the abdominal muscles for the first third of a curling movement and then take over entirely after that point to complete the contraction of a person's chest toward their lower extremities. Moreover, significant damage to muscles and bones can be incurred from repeated psoas-dominated movements. The psoas muscles exert considerable force against the lower spine. To the extent exercises are performed while a person's back is arched, the vertebrae around the psoas attachment tend to grind together and may result in permanent lower back pain as a result of disk degeneration. As such, an exercise that specifically targets the abdominal muscles without substantially contracting other muscles, such as the psoas muscles, would be desirable. Proof that the abdominals are not being utilized efficiently is seen, for example, by athletes that perform several hundred Roman chair sit-ups in an attempt to obtain a sensation of "muscle burn" in their abdominal region.
While it is possible to perform correct anatomical positioning to achieve significant isolation of the abdominal muscles during an exercise, considerable training and care is required to perform such exercising consistently to both achieve maximum effectiveness and to avoid potential injury. For example, by performing exercises in which a quarter sit-up is performed, individuals often pull too strongly with their hands behind their head, thus placing unnecessary stress on the neck and shoulder muscles and often resulting in the arching of a person's back due to increasing muscle fatigue after several repetitions of the sit-up exercise. When a person places their hands behind their neck or head during a conventional sit-up or curl, it allows the arms to pull the head and neck into hyperflexion, stretching the posterior ligaments.
There is, therefore, a need for a safe and effective exercise apparatus that can properly configure a person's anatomical structure in order to maximize the proper conditioning of abdominal muscles without consequent undesired contraction of other muscles, such as the psoas muscles, while at the same time achieving desired movement without injuring a person due to improper positioning and/or stress on various body parts. There is also a need for an apparatus that can be easily adjustable to suit different physical body frames, that supports neck and shoulder muscles without strain during an abdominal exercise and that correctly and efficiently exercises the desired abdominal muscles in a manner that promotes the desired level of fatigue so that muscles can be toned and shaped in as short a time period as possible.