Repetitive strain injury assessment

• US 5,275,174 A
• Filed: 07/16/1992
• Issued: 01/04/1994
• Est. Priority Date: 10/30/1985
• Status: Expired due to Fees

• Current Assignee: Jonathan A. Cook
• Original Assignee: Jonathan A. Cook
• Inventors: Cook, Jonathan A.
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US07/913,972
• Time in Patent Office: 537 Days
• Field of Search: 128/774, 128/782, 128/733, 33/511, 33/512, 33/515, 482/114, 482/115, 482/121, 482/122, 73/379
• US Class Current: 600/587
• CPC Class Codes: A61B 5/224 Measuring muscular strength
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence

Abstract

A method is described of assessment of a physiological state of a body joint of an animal, wherein a first body portion is connected to a second body portion and is moveable relative to the second body portion through muscular contraction. The method includes the steps of fixing the first body portion with a stationary support, restraining the second body portion with a sleeve capable of motion within a plane, applying a first selected level of resistance to the motion of the sleeve which is constant regardless of the force applied to the sleeve, and contracting the muscle in an effort to produce maximum relative movement within the plane. The rate of change of position of the second body portion is then measured during a plurality of contracting steps. Subsequently, a second selected level of resistance is applied to the motion of the sleeve which is constant regardless of the force applied to the sleeve, the muscle is again contracted in a maximal effort, and a second rate of change of position of the second body portion is measured. A system for assessment of the physiological state of a body joint is also described, including a stationary support to fix the first body portion, a sleeve to receive the second body portion and providing at least first and second levels of constant resistance to relative movement within the plane, and a device for measuring rate of change of position upon maximal exertion.

Claims

1. A method of assessment of a physiological state of a body joint of an animal wherein a first body portion is connected to a second body portion and is movable relative to the second body portion through muscular contraction, which comprises:

fixing the first body portion by a stationary support;

restraining the second body portion by a sleeve capable of motion within a plane, said plane being defined by a motion of the second body portion about a pivot point of the joint and the second body portion being connected to the first body portion by at least one muscle;

applying a first selected level of resistance to the motion of the sleeve which is constant regardless of the force applied to the sleeve so as to constrain relative movement within the plane, the relative movement being effected by the muscle;

contracting the muscle in an effort to produce maximum relative movement within the plane;

measuring a rate of change of position of the second body portion within the plane during a plurality of contracting steps;

applying a second selected level of resistance to the motion of the sleeve which is constant regardless of the force applied to the sleeve so as to constrain relative movement within the plane, the relative movement being effected by the muscle;

contracting the muscle in a maximal effort to produce maximum relative movement within the plane; and

measuring a second rate of change of position of the second body portion within the plane during a plurality of contracting steps.

2. The method of claim 1 wherein the first body portion is a human forearm and the second body portion is a human hand.

3. The method of claim 1 wherein the muscle comprises at least one agonist muscle and at least one antagonist muscle capable of producing the maximum relative movement.

4. The method of claim 1 further comprising the step of determining over a preselected time period the level of electrical activity generated by the muscle during the step of connecting.

5. The method of claim 4 further comprising the step of comparing the level of electrical activity generated by the muscle to the rate of change of position of the second body portion within the plane during a plurality of contracting steps.

6. The method of claim 5 wherein the step of comparing the level of electrical activity to the rate of change of position is performed at a selected medial body portion position.

7. The method of claim 5 further comprising comparing the level of electrical activity and the rate of change of position obtained from a test subject with a normal reference level and rate obtained from matched reference subjects.

8. The method of claim 7 wherein the matched reference subjects are of similar age, sex and height.

9. A method of assessment of a physiological state of a body joint of an animal wherein a first body portion is connected to a second body portion and is movable relative to the second body portion through muscular contraction, which comprises:

fixing the first body portion by a stationary support;

restraining the second body portion by a sleeve capable of motion within a plane, said plane being defined by a motion of the second body portion about a pivot point of the joint and the second body portion being connected to the first body portion by at least one muscle;

applying a selected level of resistance to the motion of the sleeve so as to constrain relative movement within the plane, the relative movement being effected by the muscle;

contracting the muscle in an effort to produce maximum relative movement within the plane;

determining over a preselected time period the level of electrical activity generated by the muscle during the step of contracting;

recording a background level of electrical activity produced by a muscular action that is unrelated to movement of the second body portion about the pivot point of the joint;

subtracting the background level of electrical activity from the level of electrical activity generated by the muscle during the step of contracting; and

measuring a rate of change of position of the second body portion within the plane during a plurality of contracting steps.

10. A system for assessment of a physiological state of a body joint of an animal, wherein a first body portion is connected to a second body portion and is movable relative to the second body portion through muscular contraction, which comprises:

a stationary support to fix the first body portion;

a sleeve to receive the second body portion, said sleeve being capable of motion within a plane defined by motion of the second body portion about a pivot point of the joint and providing at least first and second levels of resistance to relative movement within the plane which are constant regardless of the force applied to the sleeve; and

means for measuring a rate of change of position of the sleeve within the plane upon maximal exertion at the first and second levels of resistance, whereby the physiological status of the body joint may be assessed.

11. The system of claim 10 wherein the measuring means comprises means for recording a rate of change of position of the sleeve within the plane, said change of position achieved by motion of the second body portion about a pivot point of the joint.

12. The system of claim 10 further comprising means for measuring a level of electrical activity generated by the muscular contraction producing motion of the second body portion about a pivot point of the joint.

13. The system of claim 12 wherein the measuring means comprises means for recording a rate of change of position of the sleeve within the plane, said change of position being achieved by motion of the second body portion about a pivot point of the joint.

14. The system of claim 10 further comprising means for selection of different levels of constant resistance to relative movement within the plane.

15. The system of claim 10 wherein the sleeve is rotatably connected to a rotor shaft having an axis of rotation substantially coincident to a pivot point of the body joint.

16. A system for assessment of a physiological state of a body joint of an animal, wherein a first body portion is connected to a second body portion and is movable relative to the second body portion through muscular contraction, which comprises:

a stationary support to fix the first body portion;

a sleeve to receive the second body portion, said sleeve capable of motion within a plane defined by motion of the second body portion about a pivot point of the joint and capable of providing a constant resistance to relative movement within the plane;

means for measuring a level of electrical activity generated by the muscular contraction producing motion of the second body portion about a pivot of the joint;

means for recording a background level of electrical activity produced by a muscle contraction that is unrelated to movement of the second body portion about a pivot point of the joint; and

means for measuring a rate of change of position of the sleeve within the plane, whereby the physiological status of the body joint may be assessed.