A group of conditions that has presented a challenge to both health care providers and ergonomists are the upper extremity cumulative trauma disorders. This includes carpal tunnel syndrome, DeQuervain's tenosynovitis, cubital tunnel syndrome, Guyon's tunnel syndrome, intersection syndrome, and repetitive strain injury. There has been a steady increase in the number of reported cases of cumulative trauma disorders over the past several years. This is in part due to the increased awareness of these conditions among the general public. The increase in cumulative trauma disorders can also be attributed to the growing use of computers, although an individual can develop a cumulative trauma disorder without having used a computer. Manual use of the keyboard and/or mouse requires frequent, highly coordinated use of one's forearms, wrists, hands, fingers and thumbs for accurate data entry. This requires very brief but very frequent contractions of the muscles and their associated tendons. This may prevent adequate relaxation between contractions and lead to the development of cumulative trauma or overuse of these tissues.
The carpal tunnel, and structures therein, are the most frequently effected tissues in upper extremity cumulative trauma disorders. The structures within the carpal tunnel include the finger and thumb flexor tendons, the flexor carpi radialis tendon, the flexor carpi ulnaris tendon and the median nerve. The volar surface, or what may be called the roof of the carpal tunnel, is formed by the flexor retinaculum and the transverse carpal ligament. The dorsal surface, or what may be called the floor of the carpal tunnel, is formed by the pronator quadratus muscle, the distal radioulnar joint, the radiocarpal joint, the triangular fibrocartilage complex, the proximal row of carpal bones and the associated joint capsules and ligaments.
Carpal tunnel syndrome is a compression neuropathy of the median nerve as it passes through the carpal tunnel. The median nerve supplies sensation to the volar, also known as palmar, aspect of the thumb, index, middle finger and the radial (thumbside) half of the ring finger. Symptoms of carpal tunnel syndrome include numbness, tingling, burning sensations and pain. This involves not only the area of innervation described but may also radiate above the wrist into the forearm. Intact sensation to this part of the hand is essential for the coordinated, highly repetitive use of the fingers, thumbs and wrist flexors to operate the computer keyboard and mouse.
The development of carpal tunnel syndrome is caused by excessive pressure on the median nerve within the carpal tunnel. The carpal tunnel is a confined space and any factors that contribute to increasing pressure within the tunnel may contribute to the development of carpal tunnel syndrome. Related cumulative trauma disorders may also develop as one attempts to compensate for this increased pressure and subsequently overuse related muscles and tendons. Normal function of tendons, including the flexor tendons of the fingers and thumbs, requires relatively frictionless gliding and sliding of each tendon independent from neighboring tendons, nerves and ligaments. Overuse of these tendons can lead to inflammatory changes, that is thickening and swelling, of these tendons. Since the volume of the carpal tunnel is limited this leads to increased pressure within the tunnel, thus contributing to the development and/or worsening of carpal tunnel syndrome.
Previously reported treatment for carpal tunnel syndrome and other cumulative trauma disorders has included rest from provocative activities, anti-inflammatory medications, steroid injections, surgery, and/or the use of wrist splints either in a neutral or extended, so called cock-up, wrist position. While these measures often prove to control symptoms temporarily they have proven to be less successful in permanently controlling or relieving symptoms. Neutral or cock-up wrist splints have provided control of symptoms for some people during sleeping hours. However use of these splints during waking hours has proven to be impractical for most people due to the rigid immobilization of the wrist and partial immobilization of the base of the thumb that these splints create. In fact such restricted range of motion of the wrist and thumb may aggravate carpal tunnel syndrome and cumulative trauma disorders due to the abnormal manner in which the finger and thumb flexors and extensors would be forced to function while wearing said splint.
Permanently avoiding provocative activities may also be an impractical solution as it may be a required activity in one's occupation or adversely effect the quality of one's life, for example having to give up a sport, recreational activity or hobby. Surgical resection of the transverse carpal ligament may offer more permanent control of symptoms however there is a period of temporary disability following surgery. Additionally there are inherent risks with any surgical procedure. Also it has been proven to be an expensive method of treatment. Lastly there is a possibility of symptoms returning when one resumes their pre-surgical activities and in some cases more severe symptoms may develop due to post-surgical scar formation in the carpal tunnel.
Other prior art includes a bracelet (U.S. Pat. No. 5,468,220 to Sucher) intended to stretch the transverse carpal ligament to reduce pressure in the carpal tunnel. However it is known that stretching the transverse carpal ligament causes a temporary aggravation of carpal tunnel syndrome symptoms and therefore may not be tolerated by the individual. Additionally the stretch is achieved by three small pads which over an extended period of wearing may cause excessive tissue compression, circulatory congestion and skin irritation. Also the device requires periodic adjustments by a physician which adds inconvenience and cost to the use of said device.
Additional prior art includes a splint system intended to support the carpal tunnel by approximating the radius and ulna toward one another (U.S. Pat. No. 5,385,537 to Davini). This is accomplished in part by a semi-rigid V-shaped brace. However, the contour of the side of one's wrist is not V-shaped, causing this semi-rigid material to protrude from the wearer's wrist on both free ends. This may be impractical to wear during provocative activities due to the fact that it may become entangled in objects near the wearer's hands. This potential for entanglement also poses a safety hazard when the wearer is operating power equipment or machinery while wearing said brace. Additionally the approximation of the radius and ulna may cause excessive compression of the distal radioulnar joint, its' associated cartilage and the closely related triangular fibrocartilage complex.
What is desired and hereby presented is a splint system which does not immobilize the wrist, hand, fingers or thumb. These and other difficulties associated with prior art devices have been avoided in the novel manner by the present invention.
In view of the foregoing, it is therefore a primary object of this invention to provide a forearm splint system which achieves improved successful treatment of carpal tunnel syndrome and other cumulative trauma disorders.
A further object of this invention is to provide a forearm splint system which achieves improved successful prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders.
A further object of this invention is to provide a forearm splint system which achieves improved successful treatment and prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders, which system does not immobilize the wrist, hand, fingers or thumb.
A further object of this invention is to provide a forearm splint system which achieves improved successful treatment and prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders, which system can be worn comfortably during activities that are likely to contribute to developing symptoms.
A further object of this invention is to provide a forearm splint system which achieves improved successful treatment and prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders, which system reduces pressure in the carpal tunnel by rotating the radius and ulna towards each other, thus reducing tension in the flexor retinaculum and transverse carpal ligament.
A further object of this invention is to provide a forearm splint system which achieves improved successful treatment and prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders, which system does not protrude from the wearer's wrist and interfere with one's ability to function, nor pose a safety hazard due to potential entanglement with objects near the wearer's hand and wrist.
A further object of this invention is to provide a forearm splint system which achieves improved successful treatment and prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders, which system does not require periodic adjustments by a physician or health care provider.
A further object of this invention is to provide a forearm splint system which achieves improved successful treatment and prevention of the development of carpal tunnel syndrome and other cumulative trauma disorders, which system can be readily applied and worn comfortably for extended periods of time.
USPTO Backgrounds
USPTO Backgrounds