Effect of Isometric Plantar Flexor Muscles Exercises on the

Callus Formation of Patients with Tibial Shaft Fracture

Nasyaruddin Herry Taufik

1,*

and Nurjannah

Department of Physical Medicine and Rehabilitation, Syiah Kuala University, Banda Aceh, Indonesia

Public Health Department, Syiah Kuala University, Banda Aceh, Indonesia

Keywords: Isometric Plantar Flexor Muscle Exercise, Tibial Shaft Fracture, Hammer Scale, Callus Formation

Abstract: Osteoblast activity affects the fracture healing process. There is evidence that mechanical stimulation during

rehabilitation treatment after surgery will trigger the osteoblast activity. However, the effect of isometric

plantar flexor muscle exercise is not yet known. One of the osteoblast activity markers is callus formation.

This study aims to examine the effect of isometric plantar flexor muscle exercise on callus formation

examined by radiographic scoring method for tibial fractures (Hammer scale) among patients with tibial

shaft fracture. The study used two-group post-test-only randomized experiment. The intervention group was

given a standard of passive knee and ankle range of motion exercises and the addition of isometric training

of plantar flexor muscles, while the control group only received the standard of passive knee and ankle

range of motion exercises. The Hammer scale to describe the callus formation was compared using a two-

sample t-test for independent samples with unequal variances. The results show that the intervention group

had a significantly better Hammer scale than the control group, 2.63 and 3.06, respectively (p-value =

0.033), indicating better fracture healing. The study highlighted the effect of the addition isometric plantar

flexion exercises with range of motion exercises on fracture healing among patients with tibial shaft facture.

1 INTRODUCTION

Tibial shaft fractures are one of the most

common long bone fractures, mostly found among

young males, (Court-Brown et al., 1998) related to

sport activities and vehicle accidents (Robertson et

al., 2012;

Robertson et al., 2014; Bode et al., 2012).

Similar to any acute fracture, the treatment of tibial

shaft facture includes optimal fracture

immobilization and appropriate rehabilitation to

restore of normal physical functioning (Court-Brown

et al., 2006). Several surgical interventions are used

to treat tibial shaft fracture including intramedullary

(IM) nailing, open reduction and internal fixation

(ORIF), external frame fixation, functioning (Court-

Brown et al., 2006), and cerclage wire fixation

(Habernek, 1991; Habernek et al., 1989;

DeLisa,

2005). Then followed by timely rehabilitation

trainings are passive and active range of motion

(ROM), isometric exercises, strength training,

physical modalities, gait and proprioceptive training

(Radomski & Latham, 2008). The success of a

surgical treatment is heavily influenced by the

compliance of physical therapy recommendation

after surgery. Although, isometric and ROM

exercises are known to increase muscle strength

(Court-Brown et al., 2006), few studies have

assessed the influence of the combination of ROM

and isometric plantar flexion on callus formation

particularly for tibial shaft fracture.

The aim of this study was to compare the

outcomes of the callus formation among patients

with tibial shaft fracture administering rehabilitation

exercises with either ROM only or combination

ROM with isometric exercises after having ORIF

surgery.

2 METHODS

This two-group posttest-only randomized study was

conducted in Zainoel Abidin Hospital, Banda Aceh -

Indonesia. From July 2014 to January 2015, 34

patients with a tibial shaft fracture who has

undergone ORIF surgery received rehabilitation

treatment both at the hospital and at the patients’

Tauﬁk, N. and Nurjannah, .

Effect of Isometric Plantar Flexor Muscles Exercises on the Callus Formation of Patients with Tibial Shaft Fracture.

DOI: 10.5220/0008792402330236

In Proceedings of the 2nd Syiah Kuala International Conference on Medicine and Health Sciences (SKIC-MHS 2018), pages 233-236

ISBN: 978-989-758-438-1

233

home. The criteria for inclusion in the study were

having open fracture of the tibial shaft with category

of 1/3 medial, 1/3 proximal, and 1/3 non-articular

distal bones, being aged between 20 to 45 years at

the time of having the rehabilitation treatment, and

willing to participate in the study. Exclusion criteria

were patients with impaired consciousness, having

multiple fractures related to knee joint and ankle,

history of diabetes, and having surgical treatment

other than ORIF.

All included patients received rehabilitation

treatment after surgery either ROM only or the

combination of ROM and isometric plantar flexion

exercises depending on the randomization. Each

patient was assigned to an identified number in the

study. Patients with odd number received the

combination of ROM and isometric exercises as the

intervention group, while patients with even number

received the ROM exercise only as the control

group.

2.1 Procedure

The control group received a standard procedure of

passive knee and ankle joint ROM exercise. The

detail procedure of the ROM as follows:

 The patient was lying supine with the lower leg

in a straight state, the knee joint extension and

the ankle joint in neutral position.

 The therapist performed the flexion movement

of the knee joint to the full or the tolerance limit

of the patient's pain then returned to its original

position. The movement was repeated up to 10

times.

 The therapist then performed dorsiflexion of the

ankle to the full or the tolerance limit of the

patient's pain then returned to its original

position. The movement was repeated up to 10

times.

 Furthermore, the therapist performed an ankle

flexion movement until the full or patient

tolerance limit of pain the patient then returned

to its original position. This movement was

repeated up to 10 times.

 The ROM training was conducted for one

session, and each session was repeated for 10

times.

The intervention group received passive knee and

ankle joint ROM exercise and the addition of

isometric training of plantar flexor muscles in a

structured manner. The ROM exercise was similar to

the control group. The detail of the isometric plantar

flexion exercise is explained as follows:

 The patient was lying on his back with the

lower leg position in a straight and ankle joint at

a neutral position. The therapist performed

fixation on the ankle joint by means of one hand

holding the patient's footprint and the other

hand holding the patient's calf.

 The patient performed isometric contraction of

the plantar muscle of the flexor.

 Assessment of contraction of plantar muscle is

done by palpation on the patient's calf. Long

contraction was conducted for 10 seconds

counted using stopwatch.

 Each training was performed for three sessions

and each session was performed with 10

repetitions with each rest period of 10 seconds.

 Exercise socialization was first conducted on

the healthy foot.

Both trainings in control and intervention group

were conducted every day started from the second

day after surgery until the 28

day. When patients

were allowed to leave the hospital, the

physiotherapists continued the rehabilitation

exercises by visiting patients in their houses. The

rehabilitation training was conducted by a physician

and his assistant for all the patients in both groups.

On the 29

day, patients were examined for the

callus formation by having an x-ray examined using

radiographic scoring method for tibial fractures by

Hammer et al. (1985). If the 29

day was the

holiday (for example Saturday, Sunday or national

holidays when the hospital is closed) then the x-ray

was performed at the earliest day after holiday. The

Hammer scale is classified as described on table 1

which indicates the lower the scale, the better

fracture healing process. The radiograph

examination was performed by a radiologist who

was blinded to the patients’ training methods.

Table 1. Radiographic Scoring Method for Tibial

Fractures by Hammer et al. (1985)

Grade Callus

Formation

Fractures

Line

Stage of

Union

1 Homogeneous,

one structure

Obliterated Achieved

2 Massive, bone

trabeculae

crossing fracture

line

Barely

discernible

Achieved

3 Apparent bridging

of fracture line

Discernible Uncertain

4 Trace, no

bridging off

fracture line

Distinct Non-

achieved

5 No callus

formation

Distinct Non-

achieve

SKIC-MHS 2018 - The 2nd Syiah Kuala International Conference on Medicine and Health Sciences

234

2.2 Statistical Analysis

Statistical analyses were performed in SPSS 22 with

use of the independent t test to compare the Hammer

scale difference after surgery to examine the callus

formation which is related to fracture healing

between the patients who received ROM training

and those who received the combination ROM and

isometric plantar flexion training. The test

significance was defined as p<0.05.

3 RESULTS

Out of a total sample of 34 patients, two of them

were excluded because they missed the training

more than 4 days, resulting in 32 patients for final

analysis with 16 patients in each group. More men

(72%) than women enrolled in the study. The mean

age of all patients were 34.5 years old.

The results of the radiographic scoring method

for tibial fractures are presented in Table 2. It shows

that there is a statistically significant difference of

Hammer scale, at 0.05 level of significance, between

the intervention and the control groups indicating the

patients who received the combination training had

lower scale (2.62) than those who received the ROM

training only (3.06). The lower the Hammer scale,

the better the callus formation, resulting in better

fracture healing.

4 DISCUSSION

For patients with limb fractures, one of the important

rehabilitation goals are reducing pain and edema,

restoring range of motion and strength, preventing

muscle weakness and atrophy at the early stages, and

returning to normal physical function (Garrison,

2003). According to the results of this study, the

rehabilitation interventions by combining range of

motion and isometric training improved the callus

formation indicating better fracture healing than

having range of motion exercise only.

The result is consistent with other studies. For

example, Khosrojerdi et al., (2018) concluded that

isometric exercise reversed muscle strength among

patients with lower limb fractures. Similarly, Rhyu

et al., (2015) found that isometric movements

exercise was an effective rehabilitation method for

enhancing muscle activity. A study by Khalid et al.,

(2006) indicates that isometric exercise may prevent

muscle atrophy for patients with tibial shaft fracture.

Yousefi et al., (2012) suggested that isometric

trainings are effective in increasing bone density of

patients with lower limb injury.

Osteoblasts have receptors to pressure that

receives mechanical load stimuli which include

mechanical stresses, compressive and shear stresses.

The contraction of plantar flexor muscle during

isometric exercise provides the mechanical load to

the injured area which stimulates the osteogenesis

process (Turner & Pavalko, 1998). The process is

channeled through the extracellular matrix to

osteoblasts, osteocytes, periosteal cells, and

osteoclasts. These local mechanical stimuli produce

mechanotransduction, which is the conversion of

physical signals into signals typical of intracellular

biochemistry that discharge bone matrix to enhance

bone matrix mineralization. Osteoblasts cell wall is

activated by pressure from the receptor. This type of

mechanical stimulation can increase the proliferation

and anabolism of osteoblasts to facilitate the

reconstruction of bone tissue, contributing to the

healing process of homeostasis of bone tissue

(Burger & Klein-Nulend, 1999). Although the study

has reached its aim, the result may be confounded by

medication taken by patients

particularly analgesics as researchers did not control

the medication during the rehabilitation training.

Analgesics can affect the molecular and cellular

processes of bone regeneration that have a

significant effect on healing

(Gerner & O’Connor,

2008).

5 CONCLUSION

This study suggested that the combination of range

of motion and isometric exercises may improve the

callus formation and faster fracture healing than

using range of motion only after surgery for patients

Table 2. Mean difference of independent t-test of Hammer scale between control and intervention groups

Variable

ROM and isometric

trainin

(

n=16

)

ROM only

(

n=16

)

95% CI for Mean

Difference

t df p-value

M SD M SD

Hammer scale 2.62 0.71 3.06 0.25 -0.83, -0.03 -2.3 18.57 0.033

Effect of Isometric Plantar Flexor Muscles Exercises on the Callus Formation of Patients with Tibial Shaft Fracture

235

with tibial shaft fracture. The combination exercise

can be recommended as a standard training for

physiotherapists especially for tibial shaft fracture.

Further research is needed to assess the effect of the

combination exercise on different characteristic

patients with different fractures.

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