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

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

Upper extremity rehabilitation Shoulder subluxation Functional Use

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

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

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

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

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

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

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

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

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

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

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

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

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.

Shoulder subluxation

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

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...

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

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

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

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

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

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

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

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

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

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)

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

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

Functional use Frequency Amplitude Pulse Duration 18 Hz – 29 Hz As wide as 0- 100 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

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

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

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.

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.

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.

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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, 257-267. 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.