INTRODUCTION:

Trunk dissociation plays an important role in human movement. All activities of daily living involve various trunk dissociation patterns. It is an act done to maintain the centre of gravity close to the body during a movement. This mechanism works on the basic principle of physics. The movements of trunk dissociation take place in three different planes and along three different axes. There are frontal plane movements that take place along sagittal axis.

These movements are predominantly side to side i.e., when the upper body segment moves to right lateral side the lower body segment moves to the left side and vice versa. During such activities the trunk’s side flexors, on one side works concentrically to give direction to the movement and on the other side works eccentrically to conventional the movement. There are sagittal plane movements that take place along coronal axis. These movements are predominantly anterior and posterior. i.e., when the upper body segment moves forward the lower body segment moves backwards and vice versa. During such activities the trunk flexors and extensors work reciprocally in concentric and eccentric manner. There are transverse plane movements that take place along vertical or longitudinal axis. These movements are predominantly rotator in nature i.e., when the upper body segment moves towards internal rotation the lower body segment moves towards external rotation and vice versa. These trunk dissociation patterns are required for maintaining balance and coordination during movement.

For a normal person the line of gravity shifts to the ipsilateral side of reaching out to one side and shifts back to normal when the lower limbs move to the contralateral side, this is called anticipatory postural adjustments^1,2. This pattern is compromised in motor developmental delay, “the condition in which a child is not developing and/or achieving skills according to the expected time frame,” these children do not achieve developmental milestones at the expected time³. There are various conditions that lead to motor developmental delay in the pediatric population such as cerebral palsy, downs syndrome, Williams’s disease, brain trauma, spina bifida, metabolic disorders, premature birth etc. According to the WHO, approximately 5% of children below the age of 14 years exhibit a developmental delay or disability.Children with developmental delay not only have delayed motor function but also have disability on a wider aspect. Lack of balance and coordination affects the child’s day-to-day functional activities⁴.

From the time a baby lifts his or her head, to when an individual is well into his or her senior years, balance plays a critical role in accomplishing the functional activities of daily living. It is obvious that, physical disability can interfere with development of balance and, subsequently, gait. Balance and gait are foundational to most other motor tasks⁵. In addition, balance is an important component of perceptual-motor development, influencing laterality, directionality, and spatial orientation⁶. Cognitive disability can impair mental processing necessary for solving movement problems, including gait. Providing therapeutic intervention through balance and gait training will benefit almost every child, regardless of degree or type of disability.

Trunk is the integrating centre for all movements of the limb there is a strong influence of trunk function on balance^7,8. The trunk muscles are found to get activated before the muscles of the limbs, following impairment⁹. There are various proven studies that state the correlation between trunk impairment and balance¹⁰. The most important physical component for a normal balance is the base of support, low centre of gravity and line of gravity falling closer to centre of the base of support^11,12. When there is a trunk asymmetry all the three components are disturbed resulting in abnormal balance functions in stroke subjects (Verheydenet al, 2011)^13,14. In the hierarchy of development, trunk control is achieved before standing because the trunk muscles play a vital role in balance and support. Studies done on trunk training have proved that adding specific trunk training exercises to the regular exercise regimen have improved trunk symmetry (Mudie et al, 2002) and trunk mobility (Saeys et al, 2012)^15,16.

Trunk Dissociation Retrainer (TDR) is equipment used for the rehabilitation of stroke patients which concentrates on the wider aspects of the disability rather than just motor rehabilitation. It was used for retraining balance, gait and functional activities in hemiplegic. In a study done in 2015 it was concluded that, Trunk Dissociation Retainer is a better alternative tool in improving balance, Functional activities and gait in hemiplegic subjects compared to manual trunk dissociation training (Arunachalam et al, 2015)¹⁷. Any exercise when performed through equipment, always has an added effort from the subject. The motivation levels are always high. The equipment based exercises are always target oriented. The user can perform several repetitions in lesser duration and more effectively.

The Trunk Dissociation Retrainer was found to effectively improve the trunk function in hemiplegic patients and it was also found to be safe for rehabilitation^18,19. The present study will find the effectiveness of TDR for the pediatric population with necessary changes in the equipment called as MTDR (Modified Trunk Dissociation Retainer), for the benefit of the children with developmental delay, in training balance and gait²⁰.

MTDR – Modified Trunk Dissociation Retainer consists of two units, the wheel and the patient unit. The wheel unit consists of a metal upright with a central pivot. The axis of the central pivot is maintained at the umbilical level of the patient. The patient unit consists of a seat of adjustable height. The patient seated holds on to the gripping provided on the wheel unit and places the feet on the foot rest. Three different movements are performed with MTDR that is, when the upper end of the upright rod is moved to affected side the lower limb moves to the opposite side. The second movement is front and back, that is, when the upper end of the upright rod moved anteriorly, the lower limb moves posteriorly provides the patient unit is kept static by fixing the seat in these two movements. The third movement is rotation of the trunk that takes place by making the patient unit dynamic and the patient carries out rotation of the trunk by holding onto the wheel unit for support.

MATERIAL AND METHODS:

Study design: Quasi experimental study

Study setting: Saveetha Medical College and Hospital,

Physiotherapy outpatient department,

Saveetha University, thandalam,

Chennai – 602105

Sampling method: convenient sampling

Sample size: 10 subjects

Inclusion criteria:

· Subjects of age group – 4 to 8 years.

· Subjects of both genders

· Subjects with developmental delay

· Subjects with compromised trunk performance assessed using Trunk Impairment Scale (score not less than 2/7 for static sitting balance , 4/10 for dynamic sitting balance and 2/10 for coordination)

Exclusion criteria:

· Patients who do not comprehend to instructions / cognitive developmental delay.

· Global developmental delay

· Irritable children

· Anxiety disorders

· Attention deficit

· Children with fixed deformities (contractures)

MATERIALS REQUIRED:

Modified Trunk Dissociation Retrainer

Outcome measures:

· Paediatric Balance Scale (PBS)

· Gait velocity

Procedure:

10 individuals with developmental delay were selected based on inclusion and exclusion criteria. Detailed procedure was explained in patient’s familiar language and those who were interested, informed consent was obtained from all the participants.

The treatment protocol consisted of a pre-test, intervention and two post-tests. The pre-test and post-test were done using Paediatric Balance Scale (PBS) and Gait velocity analysis.

The intervention was given for a duration of 3 weeks, 5 times a week and each session that lasts for 90 minutes, which comprises of 60 minutes of conventional physiotherapy - 10 minutes of motor training, 10 minutes of balance training, 10 minutes of gait training 10 minutes of sensory integration, 10 minutes of functional activities, 10 minutes of hand function/ co-ordination. This also includes the rest period. Followed by 30 minutes of MTDR - 7 minutes of sagittal plane movement, 7 minutes of frontal plane movement and 7 minutes of rotational plane movement. 3 minutes of rest after each 7 minutes session.

A baseline analysis of balance and gait was done before the intervention began. Three weeks of intervention was given to the subjects following which a post-test was conducted and the patients were asked to return after three weeks and the 2^nd post-test was done to analyze the sustained effects of the intervention.

Treatment session:

Duration of each session : 90 min

Sessions : 1 session/day

Frequency : 5 days/week

Duration : 15 days

TABLE: 1 Pre-test and post-test values of PBS

	Test	Mean	Standard deviation(SD)	P value
PBS	Pre test	21.9	4.458450154	P <.05
	Post test I	43.8	2.740640639
	Post test II	45.5	3.027650354

TABLE: 2 Non – parametric analysis- Ranking scale

	SS	Df	MS	F
Between	3464.8666666667	2	1732.4333333333	508.207
Within	92.040670323	27	3.4089137156667
Total	3556.9073369897	29

TABLE: 3 Non – parametric test result

F-Statistic	Critical Value	Result	Conclusion
508.207	3.3541	Reject the null hypothesis.	The compared groups differ significantly, F(2,27) = 508.207, p < 0.05.

TABLE: 4 Trukey HSD test result

Treatments pair	Tukey HSD Q statistic	Tukey HSD p-value	Tukey HSD inferfence
Pre-test vs Post-test I	19.8394	0.0010053	** p<0.01
Pre-test vs Post-test II	21.3794	0.0010053	** p<0.01
Post-test I vs Post-test II	1.5400	0.5286640	Insignificant

Fig. 1: Graph showing pre-test and post-test values of PBS

TABLE: 5 Pre-test and post-test values of gait velocity

	Test	Mean	Standard deviation(SD)	P value
Gait veocity	Pre test	16	2.7487	P <.05
	Post test I	6.7	1.4944
	Post test II	5.9	1.2867

TABLE: 6 Repeated measures analysis of variance to find the difference between the pre-test and post-test I and II – Gait Velocity

Source	SS	Df	MS
Between-treatments	630.4667	2	315.2333	F= 82.63398
Within- treatments	103	27	3.8148
Total	733.4667	29

RESULT:

From statistical analysis made with the quantitative data revealed statistically significant difference between the pre-test and post-test values within the group.

Fig.2: Graph showing pre-test and post-test values of gait velocity

PAEDIATRIC BALANCE SCALE:

The pre-test mean value of PBS was 21.9 (SD 4.45) and post-test mean value of PBS was 43.8 (SD 2.74) this shows that post-test is greater than pre-test with P value (p <.05). Comparison between the mean values of post-test I and post-test II shows that the results have sustained.

Non-parametric- Ranking scale analysis was done for PBS for which the “F” value was calculated as 508.207 . Hence we rejected our null hypothesis and concluded that the compared groups differed significantly with p value <.05.

Multiple level comparison for PBS was done using Turkey HSD analysis (table- 4) which showed that there was significant difference between pre-test and post-test I and also pre-test and post-test II. There was no significant difference between post-test I and post-test II which shows that there was progressive improvement in the subjects but the effect of training did sustain.

GAIT VELOCITY:

The pre-test mean value of gait velocity was 16 (SD 2.74) and post-test mean value of gait velocity was 6.7 (SD 1.49) this shows that post-test is greater than pre-test with P value (p <.05). Comparison between the mean values of post-test I and post-test II shows that the results have sustained.

Parametric- Repeated analysis of variance was used for gait velocity for which the “F” value was calculated as 82.63398 . Hence we rejected our null hypothesis and concluded that the compared groups differed significantly with p value <.05 .

Multiple level comparison for gait velocity was done using Holm-Sidak (table- 6) which showed that there was significant difference between pre-test and post-test I and also pre-test and post-test II. There was no significant difference between post-test I and post-test II which shows that there was no progressive improvement in the subjects but the effect of training did sustain.

DISCUSSION:

The loss of balance and instability in gait are the major problems faced by developmentally delayed children. Trunk dissociation is seen to be the cause of these instabilities in children. There are many conventional treatment procedures that are being practiced for improving balance such as the swiss ball, but there no much focus on the dissociation. The Modified Trunk Dissociation Retrainer provides training in the sitting position unlike any other conventional treatment. Manual effort of the therapist required is reduced to more than half of that which is required during other conventional methods of treatment. Time consumption is also less while working with MTDR.

There were 10 children who participated in the study, there were no drop outs, and each child was different. Handling paediatric subjects was a challenge. Most of them were apprehensive in the beginning and later got comfortable with the equipment and the surrounding. There was nothing playful to retain the attention of the children during treatment. Few children were very cooperative during the study. Some children were short for the equipment irrespective of their age.

The treatment duration was 15days and improvement was seen in most of the subjects by the end of 2^nd week itself. Gait velocity was seen to have dramatically increased my 2weeks. Balance and stability increased in the subjects by 3 weeks. The post –test II also proved that the effects had sustained over a period of 3weeks.

This study provides a good clinical implication to therapist. Thus, MTDR can be an effective tool compared to the already existing manual techniques in improving gait and balance in developmental delay children.

In future the equipment can be designed with further modifications in the dimensions and adjustable manner for all paediatric conditions. Biofeedback can be added to the equipment. The device can be made more children friendly to grab the attention of children by making it more colourful and adding audio visual aids to encourage the children to work on it.

CONCLUSION:

From the result, it is concluded that Modified Trunk Dissociation Retrainer (MTDR) is effective in improving balance and gait velocity in children with developmental delay.

ACKNOWLEDGEMENT:

The authors are grateful to the authorities of Saveetha College of Physitherapy, Chennai.

CONFLICT OF INTEREST:

The authors declare no conflict of interest.

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Received on 02.03.2018 Modified on 12.05.2018

Research J. Pharm. and Tech 2018; 11(11): 4870-4874.

DOI: 10.5958/0974-360X.2018.00886.7

Treatments pair	Bonferroni and Holm TT-statistic	Bonferroni p-value	Bonferroni inferfence	Holm p-value	Holm inferfence
Pre-test vs Post-test I	10.6471	1.0911e-10	** p<0.01	7.2737e-11	** p<0.01
Pre-test vs Post-test II	11.5630	1.7315e-11	** p<0.01	1.7315e-11	** p<0.01
Post-test I vs Post-test II	0.9159	1.1035152	Insignificant	0.3678384	Insignificant