Diagnosis of neuromuscular dysfunction

• US 5,916,172 A
• Filed: 12/30/1997
• Issued: 06/29/1999
• Est. Priority Date: 03/29/1995
• Status: Expired due to Fees

• Current Assignee: The University of Queensland
• Original Assignee: The University of Queensland
• Inventors: Hodges, Paul William, Richardson, Carolyn Anne
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): WINGOOD, PAMELA LYNN
• Application Number:
  US08/930,376
• Time in Patent Office: 546 Days
• Field of Search: 600/546, 600/587, 600/594, 600/595
• US Class Current: 600/546
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/395 Details of stimulation, e.g. nerve stimulation to elicit EMG response

Abstract

A diagnostic apparatus for diagnosis of lower back pain (LBP) caused by neuromuscular dysfunction, said diagnostic apparatus comprising:

a monitoring means for monitoring an anticipatory muscle signal resulting from one or more electrodes associated with an anticipatory muscle and a prime mover muscle signal resulting from one or more electrodes associated with at least one prime mover muscle associated with a limb; and

a processing means for detecting a variation in the time of onset of the anticipatory muscle signal relative to the time of onset of the prime mover muscle signal for providing diagnosis of presence or absence of LBP.

There is also provided a method for diagnosis of LBP caused by neuromuscular dysfunction said method including the steps of:

(i) initiating a voluntary movement of a limb;

(ii) electrically monitoring activation of at least one anticipatory muscle relative to activation of at least one prime mover muscle associated with the limb, and

(iii) comparing time of onset of activation of the at least one anticipatory muscle relative to time of onset of activation of the at least one prime mover muscle to diagnose presence or absence of LBP.

Claims

1. A diagnostic apparatus for diagnosis of LBP caused by neuromuscular dysfunction, said apparatus comprising:

a monitoring means for monitoring an anticipatory muscle signal resulting from one or more electrodes associated with an anticipatory muscle and a prime mover muscle signal resulting from one or more electrodes associated with at least one prime mover muscle associated with a limb; and

a processing means for detecting a variation in the time of onset of the anticipatory muscle signal relative to the time of onset of the prime mover muscle signal for providing diagnosis of presence or absence of LBP.

2. The diagnostic apparatus of claim 1 wherein LBP is diagnosed when activation of the prime mover muscle occurs before activation of the anticipatory muscle.

3. The diagnostic apparatus of claim 1 wherein absence of LBP is diagnosed when activation of the anticipatory muscle occurs prior to or concurrently with activation of the prime mover muscle.

4. The diagnostic apparatus of claim 1 further comprising a signal generator means for generating one or more instruction signals.

5. The diagnostic apparatus of claim 4 wherein the signal generator means provides two sequential instructions.

6. The diagnostic apparatus of claim 4 wherein the signal generator means provides a time delay between the start of each of the instruction signals.

7. The diagnostic apparatus of claim 4 wherein the signal generator means provides a randomly variable time delay between the start of each of the instruction signals.

8. The diagnostic apparatus of claim 1 wherein the processing means provides an output signal indicative of the presence or absence of LBP when the prime mover muscle signal and the anticipatory muscle signal increase above a threshold value.

9. The diagnostic apparatus of claim 8 wherein there is a different threshold value associated with each of the prime mover muscle signal and the anticipatory muscle signal.

10. The diagnostic apparatus of claim 9 wherein the different threshold value associated with each of the prime mover muscle signal and the anticipatory muscle signal are manually adjustable.

11. The diagnostic apparatus of claim 9 wherein the processing means is adapted to calculate each of the said different threshold values.

12. The diagnostic apparatus of claim 1 further comprising a signal conversion means to convert both the prime mover muscle signal and anticipatory muscle signal into corresponding digitised signals.

13. The diagnostic apparatus of claim 12 further comprising a digital storage means for storing the digitised signals.

14. The diagnostic apparatus of claim 13 wherein the processing means is a computer or programmable processor.

15. The diagnostic apparatus of claim 14 wherein the digital storage means is part of the computer or programmable processor.

16. The diagnostic apparatus of claim 12 wherein the apparatus is adapted to average the digitised signals over a period of time to provide signal reference values.

17. The diagnostic apparatus of claim 16 wherein the processing means provides an output signal indicative of the presence or absence of LBP when the prime mover muscle signal and the anticipatory muscle signal increase above the corresponding signal reference values thereof.

18. A method for diagnosis of LBP caused by neuromuscular dysfunction, said method including the steps of:

(i) initiating a voluntary movement of a limb;

(ii) electrically monitoring activation of at least one anticipatory muscle relative to activation of at least one prime mover muscle associated with the limb; and

(iii) comparing time of onset of activation of the at least one anticipatory muscle relative to time of onset of activation of the at least one prime mover muscle to diagnose presence or absence of LBP.

19. The method of claim 18 wherein presence of LBP is diagnosed when the time of onset of activation of the prime mover muscle occurs before the time of onset of activation of the anticipatory muscle.

20. The method of claim 18 wherein the absence of LBP is diagnosed when the time of onset of activation of the anticipatory muscle occurs prior to or concurrent with the time of onset of activation of the prime mover muscle.

21. The method of claim 18 further including the step of generating one or more instruction signals to instruct voluntary movement of the limb.

22. The method of claim 21 wherein a first and a second instruction signals are generated sequentially such that the first instruction signal functions as a warning signal which informs the patient to prepare for voluntary movement of the limb associated with the prime mover muscle and the second instruction signal instructs voluntary movement of the limb.

23. The method of claim 21 wherein a time frame between each of the one or more instruction signals is varied randomly.

24. The method of claim 18 further including the step of determining when an electrical signal associated with activation of the prime mover muscle and an electrical signal associated with activation of the anticipatory muscle increase above a threshold value.

25. The method of claim 23 wherein there is a different threshold value associated with the activation of each of the electrical signals.

26. The method of claim 23 further including the step of determining a muscle signal reference value associated with respective anticipatory and prime mover muscles when relaxed by averaging signals from respective muscles over multiple measurements.

27. The method of claim 23 further including the step of averaging the electrical signals over a period of time to provide an average magnitude value.

28. The method of claim 26 further including the step of comparing each of the electrical signals when the average magnitude value of each of the electrical signals increases above a respective threshold value to provide a time sequence wherein the threshold value of the anticipatory muscle signal is related to the anticipatory muscle signal reference value and the threshold value of the prime mover muscle signal value is related to the prime mover muscle signal reference value.

29. The method of claim 26 wherein diagnosis of the presence of LBP occurs if the average magnitude value of the prime mover muscle signal increases above the threshold value thereof prior to when the average magnitude value of the anticipatory muscle signal increases above the threshold value thereof.

30. The method of claim 26 wherein absence of LBP is diagnosed if the average magnitude value of the anticipatory muscle signal increases above the threshold value thereof prior to or concurrent with when the average magnitude value of the prime mover muscle signal increases above the threshold value thereof.

31. The method of claim 18 further including the step of analysing multiple measurements to validate the diagnosis.

32. The method of claim 18 wherein the anticipatory muscle is selected from the group including transversus abdominis and multifidus.

33. The method of claim 18 wherein the prime mover muscle is selected from the group including anterior deltoid, middle deltoid and posterior deltoid.

34. The method of claim 18 wherein the prime mover muscle is associated with the upper limbs or arms of a patient.

35. The method of claim 18 wherein the prime mover muscle is associated with the lower limbs or legs of a patient.

36. The method of claim 34 wherein the anticipatory muscle is selected from the group including transversus abdominus, internal oblique, external oblique, rectus abdominis and multifidus.

37. The method of claim 34 wherein the prime mover muscle is selected from the group including rectus femoris, tensor fascialatae, biceps femoris, gluteus maximus, semi-membranosis or semi-tendonosis.

38. The method of claim 34 wherein the initial voluntary movement of the limb refers to flexion, abduction or extension of the limb.