Apparatus and method for distraction (stretching and/or straightening) of injured knee joints.
After knee surgery and in rehabilitation of sore and injured knees, it is important to distract (stretch or uncouple) the knee joint to prevent stiffness from becoming permanent. In athletes, this is frequently accomplished by having a trainer pull on the leg to distract the knee joint for a predetermined time period−10 to 20 minutes is customary. In some rehabilitation and physical therapy situations, bungee cords are attached to the ankle or a leg that has an injured knee, while the patient lies down with the cord under tension—stretching or uncoupling the knee joint. Bungee cords of varying elasticities allow customization of the tension applied. These methods, however, either require manual assistance or a controlled environment (therapy session) to be satisfactorily applied. A detailed description of the problems in knee rehabilitation and the need for stretching is described in published application U.S. 2014/0088466, together with a complicated apparatus for use in therapy, the disclosure of which is incorporated herein by reference.
In broad aspect, the invention is an apparatus and method for distraction (stretching and/or straightening) of injured or repaired knee joints. The apparatus comprises pneumatic or hydraulic cylinders that are designed to be disposed on either side of a leg with a knee to be treated. It is important that a cylinder be placed on each side of the leg to prevent equalize the pull on the knee joint. If only on one side it is likely that the knee would be pulled sidewise as well as downward. Cylinders are attached to a knee brace or other leg-holding device, secured above the knee joint, and attached to another device secured around the ankle of the leg. The leg-holding device and ankle device are not connected nor hinged together. When the cylinder is activated, (piston extended) the knee brace and ankle device are separated (moved apart) thus causing the knee joint to be straightened or slightly separated.
Referring to the drawings,
The upper knee brace is secure so that when the piston is extended, the space between the ankle brace 212 and the upper knee brace 202 is likewise extended putting tension on the knee joint and thereby stretching it. This accomplishes the desirable uncoupling or straightening of the joint—if the knee is bent, the action will tend to straighten it, and if the knee is straight, the action will uncouple or distract the joint.
Suitable cylinders include those available from Automation Direct (cylinders a07020sp—9/16 bore or a07020sp—7/16 bore), preferably those with a spring return.
Suitable hand air pumps include Silverline elite hand pump model 3mitmv8510 available from ToolTopia at tooltopia .com.
Generally, the apparatus will be fitted by an orthotic surgeon, physical therapist, or athletic/fitness trainer. The apparatus assembly will be fitted and attached to the knee and ankle braces. When properly adjusted, the assembly is tested and characteristics plotted by measuring the extension for a given pressure applied. The air pump (or hydraulic, if used) will be applied at various pressures—e.g. 2, 5, 8, 10 psi, and the displacement (and stretch) of the piston travel (distance from knee brace attachment to ankle brace attachment) measured.
A characteristic curve such as illustrated in
If a knee-lock brace is used (one that locks into a predetermined position), the practitioner, physical therapist, or athletic/fitness trainer will specify (and/or set) the brace knee position lock means in the desired treatment position of the knee joint.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Therefore, the scope of the invention should be limited only by the appended claims.
This application is a continuation in part of U.S patent application Ser. No. 15/727,738 filed Oct. 9, 2017 and claims the benefit and priority from U. S. Provisional Patent Application 62/407,783, filed Oct. 13, 2016, the contents and disclosure of both are incorporated herein by reference for all purposes.
Number | Date | Country | |
---|---|---|---|
Parent | 15727738 | Oct 2017 | US |
Child | 16919810 | US |