5Director, National Institute for the Orthopaedically Handicapped (NIOH), Kolkata, India. ABSTRACT. Background: Neuromuscular Electrical Stimulation (NMES) ...
IJTRR 2016; 5 (5): 149-156
Original Research Article
doi: 10.5455/ijtrr.000000198
International Journal of Therapies & Rehabilitation Research http://www.scopemed.org/?jid=12
E-ISSN 2278-0343
Efficacy of Neuromuscular Electrical Stimulation on Vastus Medialis Obliqus in Patellofemoral Pain Syndrome: A Double Blinded Randomized Controlled Trail Rajesh Kumar Das (MPT)1, Komal Malik (MPT)2, Bibhuti Sarkar (MPT)3, Sourov Saha (MPT)4, Dr. Abhishek Biswas (M.D, PM&R)5 1 Professional Trainee, Department of Physiotherapy, National Institute for the Orthopaedically Handicapped (NIOH), Kolkata, India 2 Professional Trainee, Department of Physiotherapy, National Institute for the Orthopaedically Handicapped (NIOH), Kolkata, India 3 Physiotherapist, Department of Physiotherapy, National Institute for the Orthopaedically Handicapped (NIOH), Kolkata, India 4 Asst. Professor, College of Physiotherapy, Nopany Institute of Healthcare Studies, Kolkata, India 5 Director, National Institute for the Orthopaedically Handicapped (NIOH), Kolkata, India ABSTRACT Background: Neuromuscular Electrical Stimulation (NMES) had found to be an effective treatment intervention for improving functional abilities in many neurological conditions. But, there is lack of literature about the role of NMES in Patellofemoral Pain Syndrome (PFPS) and existing studies show contradictory results. Objectives: To evaluate the effects of NMES on early Vastus Medialis Obliqus (VMO) activation in PFPS. Methods: Total 30 subjects with PFPS were randomized into Group-A with NMES and supervised exercise program and Group- B with supervised exercise program only. NMES used in this study was a single channel pre-programmed portable stimulator, which supplies biphasic symmetric rectangular pulses with pulse duration 20-1000 μsec, frequency 30-75 pulses per sec, time on: off 10:50 sec for 30 minutes. Outcome measures were - Visual Analogue Scale (VAS) for pain intensity during activities, Kujala Score for functional disability, Maximum Voluntary Isometric Contraction (MVIC) for muscle strength and Electromyography (EMG) for level of VMO: VL muscle activation. These parameters were measured at zero week (baseline data), 4 th week (post-treatment) and 5th week (follow up). RESULTS: Group- A (NMES) showed more improvement than Group-B in VAS, Kujala Score, VMO: VL ratio and MVIC at post treatment and follow up with significance value p< 0.05. CONCLUSION: NMES was found to be effective by decreasing pain and functional disability and improving muscle strength and activation of VMO in subjects with PFPS. Neuromuscular Electrical Stimulation (NMES), Patellofemoral Pain Syndrome (PFPS), Vastus Medialis Obliqus (VMO), Maximum Voluntary Isometric Contraction (MVIC), Electromyography (EMG). KEY WORDS:
Dr. Rajesh Kumar Das National Institute for the Orthopaedically Handicapped , India.
*Corresponding author
Photograph
IJTRR 2016; 5 (5): 149-156
INTRODUCTION The term Patello-femoral Pain Syndrome, hereafter referred as PFPS, is often used interchangeably with “anterior knee pain” or “runner’s knee”. PFPS can be defined as anterior knee pain involving patella and retinaculum that excludes other intra-articular and peripatellar pathology. (1) According to epidemiologic studies, its prevalence has been found to be about 10%-28% in general population. (2) Bowling M et al. (2010) showed the incidence rate for PFPS was 22/1000 person per year and females were 2.23 times more likely to develop PFPS compared with males. (3) In person with PFPS symptoms of aching pain commonly were arising in the retro-patellar region in the anterior aspect of the knee joint in abnormal knee postures. Pain is aggravated by compressive loading forces across the patellofemoral joint and with specific activities such as ascending and descending stairs, squatting, and prolonged sitting. (4-7) PFPS is generally considered to result from a combination of several factors, such as quadriceps dysplasia, increased Q angle, abnormal tracking of patella, patellofemoral malalignment (PFM). (8,9) Naslund et al (2006) observed that an ischemic mechanism (decreased blood flow in the patellar bone) is involved in the pathogenesis of pain in PFPS. (8) Several researchers and clinicians hypothesized that the imbalance between vastus medialis obliqus (VMO) and vastus lateralis (VL) is the main etiological factors for PFPS, but research finding in this area so far is contradictory. (10-15) Recent use of Neuromuscular Electrical Stimulation (NMES) for management of PFPS has been advocated in few studies. NMES is the transcutaneous application of electrical current to elicit a muscle contraction by activation of motor neuron axons or intramuscular axonal branches that help in strengthening of the muscles. It is being widely used for orthopaedic and neurological rehabilitation. (16) Santos R L et al (2013) found NMES was effective when associated with strength training in rehabilitation of PFPS. (17) On the other hand, a study by Bily et al (2008) on Patello Femoral Dysfunction (PFD) showed contradictory results as they did not found any statistically significant difference in pain intensity and quadriceps torque when compared efficacy of conventional exercises with NMES. (18) There is lack of literature about the specific role of NMES in PFPS and existing studies show contradictory results, which may be a reason for NMES being neglected clinically in case of PFPS. Thus, the present study has been designed to meet the above mentioned purpose. The current study thus aims to evaluate effectiveness of NMES in patients with PFPS in reducing pain, improving strength, achieving early VMO activation and improving function.
METHODS Thirty subjects with PFPS were recruited in this study from May, 2014 to February, 2015 and were randomly assigned to Group-A who received NMES with supervised exercise program (n=15) & Group-B who received supervised exercise program (n=15) only.
Simple randomization through a chit pick method was performed after eligibility was determined. This double blinded randomized controlled trail was approved by the Institutional Ethical Committee (IEC) of National Institute for the Orthopaedically Handicapped (NIOH). Aim and procedure of the study was explained to all the subjects and a written informed consent in their preferred language (English/Hindi/Bengali) was taken. Subjects: The subjects included in this study were referred from the main Assessment Clinic of NIOH, Kolkata from age of 18 to 40 yrs. The subjects were recruited if they had a history of anterior or retro-patellar knee pain that was aggravated by at least two activities that load the patellofemoral joint (eg: stair climbing, squatting, rising from sitting, prolonged sitting with knee bent (theatre sign) etc. during past 3 month, positivePatellar Grind test and McConnell test, pain intensity of at least 3 cm on a 10 cm visual analogue scale (VAS) during activity, increased Q-Angle (range >18 degrees in female, >13 degrees in male), quadriceps strength
