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 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 7  |  Issue : 3  |  Page : 165-170

Strengthening exercises versus neuro-muscular electrical Stimulation of gluteus maximus on pelvic obliquity in children with spastic diplegic cerebral palsy: A comparative study


Department of Physiotherapy, Swami Vivekanand National Institute of Rehabilitation Training and Research, Cuttack, Odisha, India

Date of Web Publication20-Jul-2018

Correspondence Address:
Dr. Patitapaban Mohanty
Swami Vivekanand National Institute of Rehabilitation Training and Research, Olatpur, Bairoi, Cuttack, Odisha
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijhas.IJHAS_117_17

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  Abstract 


INTRODUCTION: In spastic diplegic Cerebral Palsy, there is weakness of lower limbs especially in Gluteus Maximus. Biomechanically gluteus maximus tilts the pelvic posteriorly. So in spastic diplegic cerebral palsy there is anterior pelvic tilt which cause postural abnormality and difficulty in walking.
AIM OF THE STUDY: To evaluate the effect of Neuro-muscular electrical stimulation (NMES) and functional strengthening exercises on gluteus maximus strength and pelvic obliquity.
METHODOLOGY: 30 children with spastic diplegic cerebral palsy were fulfilling the inclusion criteria were taken into the study and assigned into 2 groups with 15 subjects in each group ranged from 3-12 years. Group 1: (3 girls and 12 boys) received NMES with conventional exercises. Group 2: (1 girl and 14 boys). received only conventional strengthening exercises. All the subjects underwent an initial baseline assessment of gluteus maximus isometric strength by modified sphygmomanometer and pelvic tilt by modified pelvic inclinometer. Total duration of treatment was 5 days per week for 6 weeks.
DATA ANALYSIS: The data was analysed using SPSS version 16, between groups difference for gluteus maximus strength and pelvic inclination was done by using 2X2 ANOVA and within group difference analysis was done using Multivariate test and Mauchly's sphericity test.
RESULTS: Results of the study suggested that both the control group and experimental group had a significant improvement after treatment for 6 weeks. However, the experimental group showed greater change as compared to control group.
CONCLUSION: The NMES with conventional exercises are more effective than conventional strengthening exercises alone to improve gluteus maximus strength and pelvic obliquity.

Keywords: Anterior pelvic tilt, gluteus maximus weakness, modified sphygmomanometer, pelvic inclinometer, spastic diplegic cerebral palsy


How to cite this article:
Kol S, Mohanty P, Pattnaik M. Strengthening exercises versus neuro-muscular electrical Stimulation of gluteus maximus on pelvic obliquity in children with spastic diplegic cerebral palsy: A comparative study. Int J Health Allied Sci 2018;7:165-70

How to cite this URL:
Kol S, Mohanty P, Pattnaik M. Strengthening exercises versus neuro-muscular electrical Stimulation of gluteus maximus on pelvic obliquity in children with spastic diplegic cerebral palsy: A comparative study. Int J Health Allied Sci [serial online] 2018 [cited 2020 Apr 8];7:165-70. Available from: http://www.ijhas.in/text.asp?2018/7/3/165/237255




  Introduction Top


Cerebral palsy (CP) is defined as a group of nonprogressive but changing motor impairment syndrome secondary to a lesion or anomaly in the brain arising in the early stage of development.[1] It leads to impairments such as lack of trunk control, malalignment, asymmetry in the lower limb, and soft tissue and muscle tightness which is reflected as difficulty in functional activities. This consequently affects their quality of life.[2]

The gluteus maximus muscle plays a major role in the common day-to-day activities such as sit to stand and walking. In sit to stand, strong coordinated action is required as the body weight is transferred onto the feet and the body moves upward during the vertical phase of the movement.[3] Gluteus maximus dominates the control of the pelvis during the gait cycle. At heel strike, when trunk flexes, the gluteus maximus prevents the trunk from pitching forward.[4]

Individuals tend to display a certain degree of pelvic tilt when at rest, although it is possible to perform both anterior and posterior pelvic tilt as joint actions since the pelvis has muscle attachments from the trunk and from the hip. In fact, it has been suggested that these muscle groups form a force couple about the pelvis; the hip extensors are thought to work together with the abdominals to produce posterior pelvic tilt and the hip flexors are thought to work together with the erector spinae to produce anterior pelvic tilt.[5],[6]

It has been suggested that weak or tight muscles might lead to excessive anterior or posterior pelvic tilt in normal standing posture. In this model, tight erector spinae or hip flexor muscles and/or weak abdominal and/or gluteus maximus muscles produce excess anterior pelvic tilt.[7] However, investigations exploring the effects of strengthening the abdominals have not always found a change in pelvic tilt angle despite improving abdominal muscle strength.[8]

If gluteus maximus is weakened in CP children, so they cannot stand from sitting position. Anterior pelvic tilt will be there. All day-to-day activities cannot be possible like children cannot be able to sit to stand, sanding, walking, stair climbing, and squatting.

Dodd et al. conducted a study on a systemic review of the effectiveness of strength-training programs for people with CP. The trials suggested that training can increase strength and may improve motor activity in people with CP without adverse effects.[9]

Carmick used neuromuscular electrical stimulation (NMES) as an adjunct to a task-oriented physical therapy program in three children with hemiplegia due to CP and concluded that NMES may enhance muscle contraction and provide sensation so that a child can add a weak response with effective result and assist in improving motor control.[10]

Daichman et al. examined the effect of NMES on impairment and functional skill in 13-year-old child with spastic diplegic CP. NMES was administered to the right quadriceps muscle every other day for 6 weeks, after intervention, the right quadriceps strength was increased.[11]

van der Linden et al. stimulated gluteus maximus in 22 ambulant children with CP. The experimental group received stimulation 1 h a day 6 days a week for 8 weeks apart from regular exercise. The result showed no statistical or clinical improvement in the experimental group.[12]

In a study investigating the muscle strength of children without disabilities and children with CP, Wiley and Damiano concluded that the strength of the gluteus maximus is particularly reduced in comparison with other lower limb muscles in children with CP.[13]

Artificial walking technologies, such as step-initiated, multichannel NMES, can substantially improve gait patterns and promote muscle strength in children with spastic CP. NMES may also be applied to specific lumbar–sacral sensory roots to reduce spasticity.[14]

Recruited 75 children were randomized into control, Kinesio Taping (KT), and NMES groups. NDT was applied to all children four times a week for 4 weeks. The results showed sitting subset of gross motor function measure (GMFM) and kyphosis values improved significantly in all groups (all P < 0.01), yet change levels were more prominent in the KT and NMES groups than the control group. Moreover, NMES group showed better improvement.[15]

Recruited 32 children (15 females, 17 males; mean age 10 years, 8 months; age range 5 years, 5 months–18 years, 1 month) with unilateral spastic CP and a Gross Motor Function Classification System of level I or level II were randomly assigned to either the 8-week daily NMES treatment group or control group (usual or conventional treatments). The results showed at week 8, the treatment group demonstrated significantly (P < 0.05) increased muscle volumes for tibialis anterior, anterior compartment, medial and lateral gastrocnemius, and dorsiflexion strength not only when compared to their baseline values but also when compared to the control group.[16]

Methodology

  • Study design: A pretest–posttest experimental study design was used in the study
  • Sample size: 30 children randomly allocated to two groups by chit picking. Group 1: Conventional therapy and NMES (n = 15). Group 2: Conventional therapy and functional strengthening exercises (n = 15)
  • Study duration: The study duration was 6 weeks
  • Setting: This study was conducted at Pediatrics unit of Department of Physiotherapy, SVNIRTAR, Cuttack. Approval was accorded by the Institutional Ethical Committee.


Inclusion criteria

Children diagnosed as spastic diplegic CP of either sex in the age group ranging from 3 to 12 years, could understand and follow commands given by the therapist, and could stand independently or with one-hand support for at least 10 s and not under any antispastic drug.

Exclusion criteria

Children with types of CP other than spastic diplegia, history of convulsions, with impaired cognitive function, any recent surgical procedure for correction of deformity, soft-tissue release, etc., congenital diaphragmatic hernia or any other fixed deformity, under any antispastic drug therapy.

Procedure

The mean age of children in Group 1 was 6.6 years and there were 3 girls and 12 boys in the group. The mean age of children in Group 2 was 4.9 years and there were 1 girl and 14 boys in the group.

Informed consent was obtained from parents of children who fulfilled inclusion and exclusion criteria and randomly assigned to Group 1 and Group 2 by picking up chits, marked 1 and 2. Group allocation was done by one therapist. Pretest measurements of gluteus maximus strength and pelvic tilt were made by another therapist, treatment were carried out by the third therapist.

Measurement of isometric strength of gluteus maximus by modified sphygmomanometer

Kaegi et al. found that the modified sphygmomanometer appears to be practical to use, and the high correlations found in this study for the elbow extensors suggest that reliable measurements can be obtained with this instrument.[17] Toohey et al. in a systemic review found that sphygmomanometer appears to be reliable for assessment of isometric muscle strength around hip.[18] The patients were tested in supine position, with a wooden block placed under the lower one-third of thigh, the hip at 30° flexion, neutral rotation and abduction, and knee at 40° of flexion. The arm cuff of modified sphygmomanometer was placed between the thigh and the wooden block. Patients were asked to relax and the arm cuff was inflated to a baseline pressure of 20 mmHg. Patients were asked to extend the hip by pressing the arm cuff as much as possible. This process was performed three times with a 5s resting period between each repetition. The mean of three readings was taken and the same was repeated for the other side. The baseline pressure (20 mmHg) was subtracted from the mean reading. This reading was taken as the strength of gluteus maximus in mm of Hg.

Measurement of pelvic inclination

The patients were in supported standing position with slightly lowering the clothes from waist to palpate the anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) accurately and marked using a marker pen. The modified pelvic inclinometer consisted of pelvic caliper and a bubble inclinometer. Two arms of caliper were placed over ASIS and PSIS, respectively, and reading was noted by bubble inclinometer.

Children in Group 1 were treated by conventional physiotherapy + NMES to gluteus maximus for 60 min and Group 2 by conventional physiotherapy + functional strengthening exercises to gluteus maximus.

Electrical stimulation-Enraf-Nonius combination therapy, brand of the Netherlands with rubber electrodes 3 × 2 inches, was used covered with a moist lint pad. The active electrode was placed on the most prominent part of gluteus maximus (motor point), between the sacrum and greater trochanter and inactive electrode was placed over lumbosacral junction. Wave form – asymmetrical rectangular biphasic, pulse duration – 75–100 ms, frequency – 10–30 Hz, on-off time – 5–15 s, and intensity – maximum tolerable intensity was used to produce a visible contraction of gluteus maximus. Stimulation duration was 60 min. The child was asked to contract gluteus maximus by extending at the hip when stimulation start and relax when the stimulus stops (contraction when the red light appears and relax when the red light goes off).

Functional strengthening exercises including bridging, half-bridging, half kneeling to standing, sit to stand, stepping, and stair climbing were given for 60 min.

The total duration of treatment was five sessions per week for 6 weeks.

Measurements of gluteus maximus strength and pelvic inclination were taken for each patient before start of treatment and after completion of 6 weeks of treatment.

Data Analysis

Data were analyzed using 2 × 2 ANOVA with one between factor (group) with two levels and 1 within factor (time) with two levels for strength and another data were analyzed using 2 × 2 ANOVA with one between factor (group) with 2 level and 1 within factor (time) with 2 levels for pelvic inclination.


  Results Top


Strength of gluteus maximus

As depicted in [Graph 1] and [Graph 2], there was increase in muscle strength in both groups from pre- to posttreatment measurement over 6 weeks. However, increase being more in experimental group than the functional strengthening group.



There was main effect for time F (69.137), df (1), P (0.000). There was no main effect for group F (1.052), df (1), P (0.314). There was main effect for time × group F (23.468), df (1), P (0.000).

Post hoc analysis showed that there is significant improvement in experimental group.

There was main effect for time F (130.464), df (1) P, (0.000). There was no main effect for group F (0.506), df (1), P (0.483). There was main effect for time × group F (65.372), df (1), P (0.000).

Post hoc analysis showed that there is significant improvement in only experimental group.

Pelvic inclination

As depicted in [Graph 3] and [Graph 4], there was a decrease in the anterior pelvic tilt in both groups from pre- to posttreatment measurement over 6 weeks. However, decrease was more in experimental group than functional strengthening group for both sides.



There was main effect for time F (108.544), df (1), P (0.000). There was main effect for group F (17.866), df (1), P (0.000). There was main effect for time × group F (46.873), df (1), P (0.000).

Post hoc analysis showed that there is significant improvement in experimental group.

There was main effect for time F (15.489), df (1), P (0.000). There was main effect for group F (15.146), df (1), P (0.000). There was main effect for time × group F (70.412), df (1), P (0.000).

Post hoc analysis showed that there is significant improvement in experimental group.


  Discussion Top


The overall results of the study showed that experimental group treated by conventional physiotherapy + NMES to gluteus maximus showed statistically significant improvement in gluteus maximus strength as well as pelvic inclination with time as compared to conventional group treated by conventional physiotherapy + functional strengthening exercises.

Functional strengthening exercises including bridging, half-bridging, half kneeling to standing, sit to stand, stepping, and stair climbing resulted in improved strength of gluteus maximus.

Bridging exercise causes back muscles to contribute to control spine positions and movements in a healthy population.[19] Stevens et al. supported the abovementioned view by studying the relative muscle activity and the ratios of the back muscles in two bridging exercises demonstrating similar activity levels for all back muscles in both types of bridging exercises.[20]

Kneeling position is important as it integrates contraction of hip muscles, especially gluteus maximus along with trunk in an antigravity position and also it is more functional and developmental position. From half-kneeling position, if the child is made to stand repeatedly, hip extensor contracts and relax again and again, resulting in strengthening of gluteus maximus.[21]

Quadruped position with hip extension is used as a progression of core stabilization.[19] It increases the activity of obliques to maintain a neutral pelvic and spinal posture, in effective balancing of the internal movements and lateral shear forces; but it occurs in association with ipsilateral internal oblique activity so as to make trunk a stable unit.[22]

Sit-to-stand exercise stimulates the motor control tasks as ideal neuromuscular organization to movement. It occurs when movement is in similar pattern to the goal movement and by practicing the particular movement. Training of core muscles during repeated sit to stand also occurs and thus activates a functional task.[23]

According to Mohanty P et al. (2016) the effect of conventional strengthening exercise protocol along with Neuromuscular Electrical Stimulation (NMES) in cerebral palsy children with crouch gait is more effective than conventional strengthening exercise protocol alone to improve muscle strength and motor function.[24]

Santos et al. in a study to evaluate the effectiveness of functional strength training concluded that individualized, specific, and functional strength training seems to be an alternative to rehabilitation of children with CP with high level of functional disability.[25]

Experimental group treated by NMES + functional strengthening exercises showed statistically significant improvement in gluteus maximus muscle strength from pre- to postreadings after 6 weeks of training. In the experimental group, on the right side, gluteus maximus strength improved more (50.58%) than that of the functional strengthening group (16%), whereas on the left side, gluteus maximus strength improved in the experimental group more (49.08%) than that of the functional strengthening group (8.89%). Significant improvement in experimental group could have occurred due to NMES as an additional intervention.

According to Dodd et al., NMES works on the overload principle, resulting in greater muscle strength by increasing the cross-sectional area of the muscle and selective recruitment of type-II muscle fibers.[9] Our results also support the study done by Fiky et al. who studied the efficacy of surface electrical stimulation in treatment of CP children-a systemic review.[26] It was also well supported by Comeax et al. The potential advantage of NMES is that it can enhance sensory input, thereby increasing the child's awareness of muscle function.[27] The result of the present study is found to be similar to a study done by Daichman et al. on the effect of NMES home program on impairments and functional skills of a child with spastic diplegic CP.[11]

Pelvic inclination

Our results showed that functional strengthening exercises improved pelvic inclination. This reasoning can be well explained and furnished in literature in the form of cause and pathological mechanism for pelvic tilt. As according to Preece et al. Pelvic tilt can be performed voluntarily by contraction of trunk muscles and hip muscles, that is, hip extensors work together with the abdominals to produce posterior pelvic tilt; hip flexors work together with erector spinae to produce anterior pelvic tilt.[28]

In spastic diplegic CP children, there is spasticity and weakness of gluteus maximus and other muscles coexist, so if there is weakness in hip extensors, then iliopsoas will try to keep pelvis anteriorly drop. Strengthening of gluteus maximus may tend to neutralize the force of iliopsoas and erector spinae, improving the anterior pelvic tilt.

A similar study supporting our result of improvement in pelvic inclination after gluteus maximus strengthening was done by Kim and Seo.[29] The study was done by Shin et al. also supports the results of our study.[30]

Our results that showed NMES has important role to improve pelvic inclination in children with spastic diplegic CP well explained by the gluteus maximus muscle strengthening and its effects on pelvic inclination.

The result of the present study is found to be similar to the study done by van der Linden et al. on electrical stimulation of the gluteus maximus in children with CP; effect on gait characteristics and muscle strength.[12]


  Conclusion Top


The study revealed that the effect of conventional strengthening exercise protocol along with NMES of gluteus maximus muscle is more effective than conventional strengthening exercise protocol alone in improving muscle strength and pelvic inclination.

Study limitations

The study limitations were small sample size and no carryover effects were studied.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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