1. Applications of Low frequency currents in Upper Extremity Rehabilitation and Ambulation Training
Mark David S. Basco, PTRP
Faculty
Department of Physical Therapy
College of Allied Medical Professions
University of the Philippines Manila

2. Objectives At the end of the session, you should be able to:
Discuss the principles of applying low frequency currents (LFCs) in upper extremity rehabilitation.
Discuss the principles of applying LFCs in ambulation training.
Discuss the available evidence pertaining to the use of LFCs in upper extremity rehabilitation and ambulation training

3. Upper extremity rehabilitation
Shoulder subluxation
Functional Use

4. Shoulder subluxation Common in patients who had a stroke
Why do patients who had a stroke present with shoulder subluxation?
How do we address shoulder subluxation?
Electrical stimulation
Basamaijan principle – decreased upper trapezius tone...scapula rotates and humeral head subluxates from the glenoid foosa
Treatment for shoulder subluxation
Slings
Armboard, arm trough, lapboard to support the shoulder
Overheaad slings – prevents hand edema
Electrical stimulation

5. Shoulder subluxation Electrical Stimulation Promotes muscle activity
Supraspinatus
Posterior Deltoid
Prevents muscle atrophy
Other effects of electrical stimulation on the hemiplegic shoulder
Other effects:
Believed to decrease shoulder pain associated with shoulder subluxation
May decrease spasticity due to reciprocal inhibition
Could increase mm endurance if the stimulation is aggressive
May potentially cause a reduction of shoulder subluxation as measured by radiograph

6. Shoulder subluxation Electrode placement Waveform: Asymmetric biphasic
Treatment parameters: Acccording to Gersh (1992)
Electrode placement
Waveform: Asymmetric biphasic
On:off ratio 1:3
6 – 7 hours stimulation

7. Shoulder subluxation
Is there evidence supporting the use of electrical stimulation in patients with shoulder subluxation as a result of stroke?

8. Shoulder subluxation
Efficacy of electrical stimulation in preventing or reducing subluxation of the shoulder after stroke: A meta-analysis

9. Shoulder subluxation Inclusion criteria: Randomised / quasi-randomised
Clinical diagnosis of stroke
Age of participants: More than 50 y/o
ES parameter used:
Frequency greater than 30 Hz OR a motor response was obtained

10. Shoulder subluxation Exclusion criteria:
Studies that included participants with other neurologic conditions
Studies in which ES was only one part of an intervention

11. Shoulder subluxation Included trials were categorised as either
Early ES
Participants with a stroke less than two months before being admitted OR
Late ES
Participants who had a stroke more than two months before being admitted into the study

12. Shoulder subluxation Age range:
55 – 73 years old (Early ES)
53 – 69 years old (Late ES)
All trials used ES as an adjunct to conventional therapy

13. Shoulder subluxation Stimulation parameters: Early ES Late ES
4 - 6 weeks, 5-7 days/week
Duration increased over time from 1.5 – 2 hr/day to 4 – 6 hr/day
Late ES
6 weeks, 5 days/week
Duration increased over time from
0.2 – 1.5 hr/day to 0.5 – 6 hr/day

14. Shoulder subluxation Stimulation parameters:
Minimum of 12 Hz, Maximum of 35 Hz
All reported that the stimulus produced muscle contraction
Conventional therapy not consistent among the trials
Hemi-sling, arm supports
Neuromuscular facilitation, joint mob
PT and OT

15. Shoulder subluxation How did they measure shoulder subluxation?
All used radiographic measurements in millimeters (mm)
Inconsistent methods used by the different studies to measure shoulder subluxation
Used different anatomical landmarks

16. Shoulder subluxation Efficacy of ES in preventing shoulder subluxation
Top picture in patients receving Early ES + Conventional therapy
Suggests that early ES plus conventional therapy is superior to early conventional therapy alone: produces a reduction of 6.5 mm of shoulder subluxation
Bottom picture suggests that late ES plus CT only reduces subluxation by 1.9 mm and that there is no statistically significant advantage over late CT alone.

17. Shoulder subluxation

18. Functional use Electrical stimulation has been used to:
Assist patients in regaining voluntary control over isolated muscles and joints
Encourage movement of the affected joint/s
Reduce spasticity
Relieve pain
Place the joint/s in a position that produces optimal muscle function

19. Functional use
Use of ES to improve upper extremity function is not confined to patients who had a stroke....
Aside from patients with stroke, what group of patient/s would most likely benefit from the use ES?
Patients with SCI with impaired hand function may from ES...

20. Functional use
If you’re planning to include ES in the management of your patient with SCI, you should consider these factors...
Muscles intended for ES should be accessible
Extent of damage to the stimulated muscle/s, nerve- root/s, and motor neuron/s
Function of the proximal upper limb mm should be preserved
Mm to be accessible for treatment
The amount of peripheral nerve damage restricts the application of FES
The extent of nerve damage should be determined first prior to treatment

21. Functional use “Bionic Glove” Designed to enhance the tenodesis grasp
Suitable for patients with active control of wrist flexion and extension

22. Functional use “Bionic Glove”
Has three self-adhesive surface stimulation electrodes placed over motor points
- Detects wrist flexion and extension

23. Functional use “Bionic Glove” Used with a position transducer
When the patient flexes the wrist
Finger extensors are stimulated to generate hand opening
When the patient extends the wrist
Finger flexors are stimulated for hand closure
- Detects wrist flexion and extension

24. Functional use
Is there evidence to support the use of ES to improve upper extremity function in patients who had a stroke?

25. Functional use
Meta-analysis examining the effectiveness of electrical stimulation in improving functional use of the upper limb in stroke patients
Most of the included studies used ROM, shoulder subluxation, and pain as an outcome measure.
Only 1 of the 5 studies incorporated outcome measures that tests UE function
Box and Block timed manipulation test
Motor Assessment Scale
Fugl-Meyer

26. Functional use In the study by Cauraugh et al. (2000)
30-minute treatment session
Includes PROM and gentle stretching
ES parameters
1 sec ramp up, 5 sec on, 1 sec ramp down
50 Hz, 14 – 29 mA
Improvements were demonstrated in grasping small objects and sustained extensor contraction

27. Functional use In the study by Cauraugh et al. (2000)
Limitations of the study
Small sample size n = 11
Treatment not readily applicable to clinical setting

28. Functional use
Is there evidence that a specific stimulation characteristic is associated with greater improvements in upper extremity control in patients with stroke?

29. Functional use
Relation between stimulation characteristics and clinical outcome in studies using electrical stimulation to improve motor control of the upper extremity in stroke. (2005)

30. Functional use In this study... Inclusion criteria
ES applied to the affected upper extremity in patients with stroke
ES provoking mm contraction
Application of ES with surface electrodes
Clinical research
Relevant outcome measures for motor control
Separate results for the upper extremity
English, German, French, Dutch

31. Functional use In this study... Stimulation characteristics refer to:
Device applied
Method of stimulation
Target mm
Duration
Setting for frequency, amplitude, pulse width

32. Functional use Frequency Amplitude Pulse Duration 18 Hz – 29 Hz
As wide as mA to as narrow as 30 – 45 mA
Pulse Duration
200 – 300 microseconds
Adjusted for optimal contraction and patient comfort
500 microseconds
19 trials...
12 were RCTs, 2 non-RCT, 2 multiple baseline design, 3 case-series

33. Functional use Rationale for a particular setting
None of the authors provided rationale for specific pulse duration or frequency
4 studies reported that pulse duration and frequency were adjusted to patient commfort
Apart from mm response and patient comfort no fundamental arguments were presented for specific parameters

34. Functional use Muscles stimulated Duration
Wrist and/or finger extensors
Elbow extensors and shoulder abductors
Duration
30 mins, once a day – 1 hr, thrice per day
2 weeks – 3 months

35. Functional use This study found out that...
No relationship exists between the specific setting of stimulation parameters, duration of stimulation, subject characteristics, and clinical outcome.

36. Functional use This study found out that...
The common end-point in all studies was mm contraction, despite the differences in parameter setting.
Muscle contraction may be more crucial rather than stimulus parameters.

37. Functional use This study found out that...
It appears that triggered stimulation is more likely to yield improvements in motor control than non- triggered stimulation
However, the inability to detect a relationship between stimulation characteristics does not mean that a clinically relevant relationship does not exist.

38. Ambulation Training Patients with Spinal Cord Injury
Patients who had a Stroke

39. Patients with Spinal Cord Injury
Provide patients with thoracic or low cervical levels to perform activities without the use of wheelchair
Standing
Transfers
Stepping short distances

40. Patients with Spinal Cord Injury
The system requires a continuous open-loop stimulation of the trunk, hip, and knee extensors

41. Patients with Spinal Cord Injury
Some systems employ percutaneous implanted electrodes
Advantages of implanted electrodes
Convenience
Cosmesis
Reliability
Repeatability

42. Patients with Spinal cord injury
Successful use of the ES system for ambulation requires: complete / incomplete SCI
Voluntary control of the UE
Strong and functional UE for ambulation
The systems enable the patient to walk for
Limited period of time
Controlled environment
Needed to maintain stability and balance during walking

43. Patients with Spinal cord injury
Disadvantage:
Require significant physical effort
The metabolic energy currently required to walk with ES is too high to make it a practical alternative to the wheelchair.

44. Patients with Spinal Cord Injury
“Parastep Electrical Stimulation System”
Designed for patients with complete paraplegia
Composed of 6 stimulation channels

45. Patients with Spinal Cord Injury
“Parastep Electrical Stimulation System”
2 channels: peroneal nerves
2 channels: Quads
2 channels: paraspinals OR gluteus maximus / minimus

46. Patients with Spinal Cord Injury
“Parastep Electrical Stimulation System”
During stance
Quads, gluteus
During swing
Peroneal nerve
Stimulation triggered by a switch attached to the walker / crutch

47. Patients who had a stroke
Principal function of ES in ambulation training is:
Symmetric
Energy-efficient safe gait pattern
Community ambulation

48. Patients who had a stroke
During the swing phase of gait:
Diminished ankle dorsiflexion
Decreased knee flexion or hip flexion
During the stance phase of gait:
Diminished control of weight-bearing mm
Compensatories??? Role of ES???
Compensatory strategies:
Circumduction
Dragging
Vaulting

49. Patients who had a stroke
In searching for studies investigating the use of ES in gait training:
Most of the articles incorporated ES with gait training using a body-weight supported treadmill
Some of the studies utilized implanted electrodes

50. Patients who had a stroke
Ng et al. (2008) published a study entitled:
A pilot study of randomized clinical controlled trial of gait training in subacute stroke patients with partial body-weight support electromechanical gait trainer and functional electrical stimulation

51. Patients who had a stroke
30 minutes of upper limb and trunk mobility training
20 minutes of gait training on gait trainer with FES (intervention)
10 minutes of lower limb training
1.5 hours of multi-disciplinary treatment

52. Patients who had a stroke
FES parameters:
Rectangular pulse
400 micro sec (pulse width)
0.3 sec ramp up/down
Electrode plecement
Quadriceps
Peroneal nerve

53. Patients who had a stroke
Results:
Subjects in all 3 groups (CGT, GT, GT+FES) showed statistically significant improvement in terms of:
Mobility independence
Functional ambulation
Gait speed
All 3 groups showed continued improvement at the 6-month follow-up

54. Patients who had a stroke
Thoughts in mind....
Results of the study may have been influenced by natural recovery
Gait trainer is not readily available in our country
The small effect size when Gait Trainer alone was compared with Gait Trainer + FES may suggest that adding FES may result in additional cost for the patient
- Mean time post-stroke among the three groups were 2.5, 2.7, 2.3

56. References
Gersh, M.R. (1992). Electrotherapy in rehabilitation. Philadelphia: F.A. Davis.
Shumway-Cook, A., & Woollacott, M.H. (2001). Motor control: Theory and practical applications. Philadelphia: Lippincott Williams & Wilkins.
Ada, L., & Foongchomcheay, A. (2002). Efficacy of electrical stimulation in preventing or reducing subluxation of the shoulder after stroke: A meta-analysis. Australian Journal of Physiotherapy, 48,
de Kroon, J.R., Ijzerman, M.J., Chae, J., Lankhorst, G.J., & Zilvold, G. (2005). Relation between stimulation characteristics and clinical outcome in studies using electrical stimulation to improve motor control of the upper extremity in stroke, Journal of Rehabilitation Medicine, 37, 65 – 74.
Popovic, M.R., Curt, A., Keller, T., & Dietz, V. (2001). Functional electrical stimulation for grasping and walking: Indications and limitations. Spinal Cord, 39, 403 – 412.
Griffin, J.W. (1986). Hemiplegic shoulder pain. Physical Therapy, 66,1884 – 1893.
De Lisa, J.A. (2005). Physical medicine & rehabilitation: Principles and practice. Philaddelphia: Lippincott Williams & Wilkins.
Ng, M.F.W., Tong, R.K.Y., & Li, L.S.W. (2008). A pilot study of randomized clinical controlled trial of gait training in subacute stroke patients with partial body-weight support electromechanical gait trainer and functional electrical stimulation: Six-month follow-up. Stroke, 39, 154 – 160.