ito test does height of the pad affect back muscle endurance juanita e. soans, keerthi rao, chandra...

31

ITO TEST: DOES HEIGHT OF THE PAD AFFECT BACK MUSCLE

ENDURANCE?

Juanita E. Soans*, Keerthi Rao**, Chandra Iyer***, Dnyanda Newasekar****

ABSTRACT

Background: Decreased back muscle endurance is sometimes associated with high rates of low back

pain. Ito test is a safe and reliable test for assessing trunk extensor muscle endurance, however it limits

recognition due to lack of studies and absence of standardized testing procedure. Hence this study

aims to find out whether the height of the pad that is to be used while performing the test has any effect

on back muscle endurance in normal healthy individuals. Methodology: 84 healthy college volunteers

were recruited in the study. A pilot study was conducted to find out the optimal height of pad that can

be used for conducting Ito test. Back extensor endurance was evaluated using a foam pad of height 5,

6.5 and 8 centimeters. Results: There was no significant difference in trunk extensor endurance with

different height of the foam pad. Conclusion: Any height of the pad ranging from 5 to 8 centimeters

can be used for assessing back muscle endurance, however the self reported comfortable height of the

pad was 5 centimeters for most of the healthy participants.

Keywords: Ito test, back endurance, low back pain

INTRODUCTION

Muscular endurance is the ability of an isolated

muscle group to perform repeated contractions

over a period of time (dynamic endurance) or

sustain a contraction over time at a certain level

(static endurance)1,2. Decreased static

endurance in back extensors is sometimes

ISSN: 2277-1700 ● Website: http://srji.drkrishna.co.in ● URL Forwarded to: http://sites.google.com/site/scientificrji

32

associated with high rates of low back pain,

decreased proprioceptive awareness, poor

balance, decreased productivity at work place,

increased muscular fatigability and overload on

soft tissues and passive structures of the spine.3

Therefore, measurement of trunk muscle

endurance is potentially important for

identifying the risk factors, as prognostic

indicators, for planning treatment goals and

measuring patient’s progress.4 Hansen JW

developed the first test for evaluating isometric

back extensor endurance.5 Troup and Chapman

evaluated muscle fatigability by surface

electromyography in patients during this test.6

After a study of Bieiring- Sorensen in 1984,

which was published in the Spine journal, this

test came to be known as Sorensen test

structures of the spine7.

Although there are no gold standards for

measurement of trunk endurance, Sorensen test

is the most popular method of assessing trunk

extensor endurance. However there are some

disadvantages pertaining to the use of this test

in patients with chronic low back pain.8 It

increases the lumbar lordosis because of

extended hip and knee during the test which

can produce bulging of intervertebral disc and

buckling of ligamentum flavum followed by

reducing the intervertebral foramen. The

hyperextension of lumbar spine may aggravate

pain.9 Also a study by Callaghan et al,

estimated that the compression load imposed on

spine during Sorensen test was 4000N, slightly

above the value recommended by the National

Institute of Occupational Safety and Health in

1981.10 To overcome these disadvantages Ito et

al developed a new method based on Sorensen

test and studied its reliability, safety in

application of this method and established its

validity by evaluating the endurance using this

test in 190 healthy individuals and in

individuals with chronic low back pain. The

reliability of this test in healthy individuals is,

ICC= 0.97 for trunk extensor muscles.8 Also,

maximal neck flexion and gluteal muscle

contraction included in the test procedure are

supposed to be the most optimal position for

decreasing lumbar lordosis and for activating

the lumbar erector spinae muscle to the

maximum.11 Muller et al in his study showed

that Ito test has a good criterion validity and it

can assess back extensor muscle endurance

more specifically as compared to Sorensen

test.12

Although, Ito test had a very high test-retest

reliability and did not seem to induce pain or

increase spinal loads the factors that limit the

recognition of Ito test includes lack of studies,

absence of standardized test procedures like the

type of pad used and extent of raising the upper

body and theoretical risk of exaggerating the

lumbar lordosis.8,10 Hence our study aims at

determining the most appropriate height of pad

to assess back muscle endurance during Ito test

in normal healthy individuals.

METHODOLOGY

Eighty-four healthy college volunteers (53

females and 31 males) between 18 – 25 years

of age who volunteered for the study from

Scientific Research Journal of India ● Volume: 3, Issue: 2, Year: 2014

33

College Of Physiotherapy, Pravara Institute of

Medical Sciences, Loni were recruited. The

study was conducted from March 2013 till June

2013. The participants were selected by

convenience sampling and were screened based

on the exclusion criteria by physiotherapist who

later were involved with data collection.

Exclusion criteria were a history of

symptomatic low back pain within one year to

the time of the study, any obvious spinal

deformity, individuals participating in high-

intensity regular exercise or elite sports at

competitive level or individuals involved in any

prior systematic exercise program of lumbar or

hip extensor muscles, a history of

cardiovascular disease representing

contraindications to exercise or any disability

limiting the ability to exercise. The participants

were informed about the study and a written

consent was obtained before any measurements

were taken. Anthropometric data like height,

weight, BMI and abdominal girth of the

participants were calculated. Height was

measured using a stadiometer to the nearest 0.1

cm. Body weight was taken with light clothes

and measured to nearest 0.1 kg using a

weighing scale caliberated from 0-120 kgs with

the participant in standing position and shoes

off. BMI was calculated using the above data.

Abdominal girth was calculated using a

measuring tape at the level of the umbilicus to

the nearest 0.1 cm.

Before taking the readings the participants were

demonstrated the procedure of the test and were

also asked to perform it themselves. They were

encouraged to clarify their queries, if any and

all queries were addressed for complete

familiarization of the test. For evaluating the

back extensor endurance the participants were

asked to lie in prone position with a foam pad

(figure 1) under the lower abdomen.

Figure 1: Foam pad used for the test

This foam is medium rubber, high density and

has a medium to soft feel depending on the

body weight of the sleeper. It offers a high

degree of comfort and will retain its shape and

density. Participants were made to perform the

test in the following manner. The foam pad was

first placed below the lower abdomen of the

participants and they were asked to lift the

sternum off the plinth and hold the position as

long as they could upto a maximum of 300

seconds8. While performing the test participants

were asked to maintain maximum flexion at

cervical spine with pelvic stabilization through

contraction of glutei, the most optimal position

for reducing lumbar lordosis and activating the

lumbar erector spinae (Figure 2).


34

Figure 2: Participant performing ITO test

The pattern of selection of height of the foam

pad with which the participants were to start the

test was done by block randomization method

which was computer generated. The time for

which the participants could hold the test

position with the height of the foam pad was

measured in seconds using a stop watch. After

a rest period of 10 minutes, the test was

repeated with the same height of the pad and

similarly 2 readings were taken. An average of

the two readings was calculated and

documented for that height of the foam pad to

obtain highest accuracy and decrease any

manual error. The criteria for stopping the tests

were trick movements, altered pain sensation

and pain tolerance. The participants were called

the next day and the same procedure was

repeated with the other height of the foam pad

on the consecutive day. The main purpose of

taking two readings was to decrease fatigability

and for obtaining the best value for each height

of the pad. Before starting with the data

collection a pilot study was conducted with ten

participants to find out the optimal height of the

pad that can be used as reference for this study.

For any height below 5 cms in height, the

participants reported an absence of fulcrum

through which they could maintain the upper

body in the desired position, and for any height

above 8 cms the participants felt excessive

pressure on their abdomen and pain in the low

back which averaged 5.3 on VAS. Any height

greater than 8 cms was also flattening the

lumbar lordosis more than that required while

performing the Ito test. The criteria for stopping

the test were trick movements, altered pain

sensations, and pain tolerance.

Based on the results obtained, the participants

performed the test with a foam pad of 5, 6.5

and 8 centimeters in height. All the tests were

performed two hours after the last meal taken

by the participants. After each test the

participants were asked to rate their level of

discomfort on VAS so as to find out the height

of foam pad which was most comfortable.

STATISTICAL ANALYSIS:

The statistical analysis was done using Graph

Pad Instat Trial Version 13.3. ANOVA with

repeated measures was used for data analysis

and p<0.05 was considered to be statistically

significant.

RESULTS:

The baseline data for participants are as follows

and represented in table 1.

Participants Males

(n= 31

Females

(n=53)

Age

(years) 21.20 ± 2.31 21.9 ± 1.97


35

BMI

(kg/m2) 20.26 ± 3.49 20.19 ± 2.84

Abdominal

girth

(cms)

87.12 ± 10.31

76.18 ±

12.83

Table 1: Baseline demographic data of

participants

BMI of all participants were 20.26 ± 3.49

kg/m2 and 20.26 ± 3.49 79 ± 10.3 kg/m2 for

male and female participants respectively and

did not show co-relation to discomfort

experienced by them while performing the test

with different heights of the foam pad. The

abdominal girth for both male and female

participants were 87.12 ± 10.31 and 76.18 ±

12.83 centimeters respectively. The mean

holding time of all participants with pad height

of 5, 6.5 and 8 centimeters were 69.54 ± 36.79,

70.20 ± 44.96 and 68.78 ± 33.79 seconds

respectively.(figure 3)

Figure 3: Mean Holding Time

Statistical analysis was done using ANOVA

with repeated measures with p < 0.05. This

shows that results obtained were not

statistically significant leading us to conclude

that height of foam pad does not actually alter

the endurance. It was found that 72% of

participants self reported that a height of 5

centimeters of pad was most comfortable while

performing the test as compared to 6.5 and 8

cms.

DISCUSSION:

The results of the present study show that there

was n significant alteration in back muscle

endurance with different height of foam pads.

Also, most participants reported that 5

centimeter height of foam pad was most

comfortable. In our opinion the height of the

foam pad did not vary much with respect to

each other in order to change the kinematics or

coupled movements of the muscles. Time, as a

measure of endurance of low back musculature,

varies with intensity of loading and with

posture. The Ito test, as compared to Sorensen

test is safe, reliable and easy to perform and

doesn’t require any other equipment apart from

a foam pad. In the present study, a pilot study

was initially conducted to find out the optimum

height of the pad that can be used. The height

of the pad was kept between 5cms and 8cms

beyond which the participants reported

discomfort while performing the test. On

interrogation participants reported that

increased height of the foam pad placed below

the lower abdomen created excessive

compression which made it difficult for them

to breathe and reduced their performance. In

our opinion this is because a trunk extension

from 45 degrees of trunk flexion needs


36

dynamic pelvic and trunk movement. The leg

muscle will extend the pelvis, and the lumbar

muscles will stabilize and extend the lumbar

region on the pelvis whereas thoracic muscles

will lift the trunk.13 Therefore more the height

of the pillow the glutei muscles have to contract

more in order to stabilize the pelvis and the

thoracic muscles will work in order to clear the

sternum off the plinth during extension. Also

lesser the height of the pillow the compression

on the lower abdomen is less thus reducing the

discomfort in breathing. In another study

conducted by Muller et al, an EMG study to

find out the criterion validity of Ito test, a foam

roll of 0.2 m in diameter, the density of which

was not stated in the study was used to evaluate

the trunk extensor endurance.12 However, in

our study participants felt abdominal

discomfort and pain with any height above 8

centimeters. Another interesting observation

was that participants with greater abdominal

girth reported more comfort with a greater

height of the pad as compared to other

participants however the co-relation of this was

beyond the scope of this study.

The participants in the study were healthy

young adults hence the results cannot be

generalized to population with low back pain.

Evaluating back endurance muscle in patients

with low back pain using different height of

pad would have been difficult for the patients

because of repeated test procedures resulting in

aggravation of pain, hence this study was

conducted on normal individuals to find out the

optimal length of pad that can be used while

performing the test which would be

comfortable to the patients. Future scope of the

study may include finding the co-relation

between the height of the pad and abdominal

girth. Lastly as proposed in the original study

lumbar lordosis during the test should be

evaluated either by radiography or by using a

flexicurve.

CONCLUSION:

It can be concluded that any height of the foam

pad made of medium rubber and high density

having soft feel ranging from 5 to 8 centimeters

can be used for assessing back muscle

endurance however the self reported

comfortable height of the pad was 5

centimeters for most of the healthy participants.

ACKNOWLEDGEMENT:

We would like to thank the participants in the

study for their kind co-operation.

REFRENCES

1. Karen H, Glenn TM. Principles of aerobic exercise. IN: Kisner C, Colby LA, Therapeutic Exercise: Foundations

and Techniques, 5th edition, Jaypee Brothers, New Delhi, 2007.

2. Mayer T, Gatchel R, Betancur J, Bovasso E. Trunk muscle endurance measurement: isometric contrasted to

isotonic testing in normal subjects. Spine, 1995:20:920-926.

3. Chidozie M, Olusola A, Rufus A.Reference values of static back extensor muscle endurance in healthy Nigerian

adults, Med Princ Pract, 2009:18: 345-350.


37

4. Julie M, Elspeth F, Paul S, Brad Br, Caroline G.Interrater Reliability of Six Tests of Trunk Muscle Function and

Endurance, JOSPT , 1997:26 (4): 203-208.

5. Hansen JW. Postoperative management in lumbar disc protrusions. I. Indications, method and results II. Follow-

up on a trained and an untrained group of patients, Acta Orthop Scand, 1964:17(Suppl 71):1-47

6. Troup JD, Chapman AE. Changes in the waveform of the electromyogram during fatiguing activity in the muscles

of the spine and hips: the analysis of postural stress. Electromyogr Clin Neurophysiol, 1972:12:347-365

7. Beiring S. Physical measurements as risk indicators for low back trouble over a one year period, Spine, 1984:9:

106-119.

8. T Ito, Osamu Shirado, Hideki Suzuki, Masaaki Tokahashi, Kiyoshi Kaneda. Lumbar trunk muscle endurance

testing: An inexpensive alternative to machine for evaluation, Arch Phys Med Rehab, 1996:77:75-9

9. White AA, Punjabi MM. Clinical biomechanics of spine, Philadelphia, Lippincott co.1990:379-474

10. Christophe D, Marc V, Christophe D, Jean MC. Spinal muscle evaluation using the Sorenson test: a critical

appraisal of literature. Joint Bone Spine, 2006:73:43-50.

11. Shirado O, Ito T, Kaneda K, Strax TE.Electromyographic analysis of four techniques for isometric trunk muscle

exercises. Arch Phys Med Rehab,1995: 76:225–9.

12. Muller R, Strassle K, Wirth B. Isometric back extensor muscle endurance: An EMG study on the criterion validity

of the Ito test. J Electromyograph and Kinesiology, 2010:20:845-850

13. Eline MD, De Ridder, Jessica OV, Andry V, Guy V, Lieven D. Posterior muscle chain activity during various

extension exercises: an observational study, BMC Musculoskelet disord, 2013:14:204.

CORRESPONDING AUTHOR:

*Final year M.P.Th (Orthopaedics) student, College of Physiotherapy, Pravara Institute of Medical

Sciences(DU), Loni, Maharashtra, India. Email Id: [email protected]

**M.P.T, Associate Professor, College of Physiotherapy, Pravara Institute of Medical Sciences(DU),

Loni, Maharashtra, India.

***M.P.T, Assistant Professor, College of Physiotherapy, Pravara Institute of Medical Sciences(DU),

Loni, Maharashtra, India.

****B.P.Th, College of Physiotherapy, Pravara Institute of Medical Sciences(DU), Loni, Maharashtra,

India.

ito test does height of the pad affect back muscle endurance juanita e. soans, keerthi rao, chandra...

Documents