Spasticity Assessment through Pendulum Testing in Individuals

with Tetraplegia Undergoing Rehabilitation with Neuromuscular

Electrical Stimulation

Eliza Regina Ferreira Braga Machado de Azevedo

Renata Manzano Maria

, Renato Varoto

Karina Cristina Alonso

and Alberto Cliquet Junior

1, 2

Biomechanics and Rehabilitation Lab., Department of Orthopedics and Traumatology, Faculty of Medical Sciences,

University of Campinas – Unicamp, Campinas, Brazil

Biocybernetics and Rehabilitation Engineering Lab., Department of Electrical Engineering, University of São Paulo,

São Paulo, Brazil

Keywords: Spasticity, Tetraplegia, Pendulum Test, Neuromuscular Electrical Stimulation.

Abstract: Objective: To analyze the effects of different neuromuscular electrical stimulation (NMES) protocols on

spasticity improvement in subjects with tetraplegia. Methods: 13 patients with tetraplegia went through the

pendulum test evaluation before and after NMES treatment. During tests an electrogoniometer was placed

on a leg to measure leg oscillations and knee angles. Individuals were divided in two groups according to

the treatment: gait group with NMES (n=6) and exercise group with NMES (n=7) Results: Relaxation

index, test duration in seconds, angle of the first swing and rest angle of the leg in both legs were assessed

before and after the treatment for both groups. Most differences were observed in the gait group.

Conclusion: Both treatments with NMES have shown to be effective treatments for spasticity improvement

in individuals with tetraplegia.

1 INTRODUCTION

The spinal cord injury brings many complications to

the patients such as recurrent urinary infections,

osteoporosis, cardiovascular defects, muscle atrophy

and spasticity (Carvalho et al, 2001; Carvalho et al,

2006; Carvalho et al 2005; Sepulveda et al, 1997).

Treatments with neuromuscular electrical

stimulation (NMES) can minimize these

complications.

Different NMES techniques have been used from

12 channel stimulation down to 4 channel, which is

considered the minimum to generate gait after a

complete spinal cord injury. In this case, NMES is

applied to quadriceps muscles to promote knee

extension and fibular nerve which generates the

flexion withdrawal reflex (Rose J Gamble JG,

1993).

The spinal cord injury paralyzed muscle is

mainly composed by fast atrophied fibers. And when

it is electrically activated produces smaller force and

goes into fatigue quickly. So, it is necessary to

condition the atrophied and paralyzed muscle before

gait training (Rose J Gamble JG, 1993).

Besides muscle atrophy, spasticity is also

minimized by the use of NMES. Spasticity impacts

on the patients’ quality of life. It is easy to be

detected but difficult to be quantified. A subjective

assessment often used is the Modified Ashworth

Scale (Leitão et al, 2006).

Another assessment that also measures spasticity

but as an objective way is the pendulum test, created

by Wartenberg in 1951. This test version was

modified using an electrogoniometer to capture

variations in range of motions and oscillations of the

knee and has been used in individuals with spasticity

(Badj et al, 1982; Badj et al, 1984).

Recently, a device to perform the pendulum test,

consisting of an electrogoniometer and software for

visualization and data processing was built (Maria et

al, 2013).

Therefore, it becomes rather important to analyze

the effects of different NMES treatments on

spasticity improvement in subjects with tetraplegia.

Regina Ferreira Braga Machado de Azevedo E., Manzano Maria R., Varoto R., Cristina Alonso K. and Cliquet Junior A..

Spasticity Assessment through Pendulum Testing in Individuals with Tetraplegia Undergoing Rehabilitation with Neuromuscular Electrical Stimulation.

DOI: 10.5220/0004731100910094

In Proceedings of the International Conference on Biomedical Electronics and Devices (BIODEVICES-2014), pages 91-94

ISBN: 978-989-758-013-0

 2014 SCITEPRESS (Science and Technology Publications, Lda.)

2 METHODS

Thirteen patients, all male with tetraplegia and

lesions over two years old were recruited. The injury

level ranged from C3 to C7. This study was

approved by the local Ethics Committee.

All individuals went through pendulum test

evaluation before and after the treatment at The

Biomechanics and Rehabilitation Laboratory of the

UNICAMP Clinical Hospital. They were positioned

on a chair with the trunk at an angle of 60 flexion

(figure 1). During tests, a flexible fiber optic

electrogoniometer was placed (model Shape Sensor

S700Joint Angle, Meancurand Inc. figure 2a) on a

leg of the patients in order to measure the

oscillations of the leg and angles of the knees (figure

2b).

Figure 1: Patient test position on a chair with the trunk at

an angle of 60º flexion.

The individuals were divided in two groups

according to the treatment: a gait group with NMES

(GG: n=6) and exercise group with NMES (EG:

n=7).

All subjects had their quadriceps femoris and

fibular nerve stimulated by a 4 channel electrical

stimulator with 25Hz, monophasic rectangular

pulses with 300µs duration and a maximum intensity

of 150V. In the EG group each patient was trained

for 20 minutes of knee extension under quadriceps

stimulation and 15 minutes under fibular nerve

stimulation.

In the GG group, individuals went through a

treadmill gait using NMES and body weight support

(40% of body weight reduction) at a speed of 1.2

km/h for 20 minutes. Physiotherapists helped move

the legs through the gait cycle.

All the measurements were performed three

times on both legs before and after the treatment for

subsequent data analysis (mean and standard

deviation).

Figure 2: a) Electrogoniometer Shape Sensor S700, b)

Electrogoniometer positioning.

3 RESULTS

In table 1 and 2 the anthropometric data of gait

group and exercise group, respectively, can be

observed (age, body mass index – BMI, neurological

level, duration of injury and medication).

Through the pendulum test were evaluated:

relaxation index (RI), obtained by the end angle of

the leg divided by the angle of the first swing of the

leg; test duration in seconds; angle of the first swing

that is, the first angle of knee flexion (Fang) and end

angle or angle of rest of the leg (Restang).

All data were analyzed before and after the two

different treatments on both legs and are shown in

tables 3 and 4.

Most differences were observed in the gait

group.

BIODEVICES2014-InternationalConferenceonBiomedicalElectronicsandDevices

Table 1: Gait group anthropometric data.

Patients Age

(years)

BMI Neurological

level

Injury

duration

(years)

Medication/

day

1 27 20.78 C5B 8 ‐‐‐

2 29 24.66 C4A 7 Baclofen

1pill

3 39 22.59 C4B 16 ‐‐‐

4 25 16.12 C5C 6 ‐‐‐

5

6

34

45

21.65

23.59

C7A

C4B

11

16

‐‐‐

Mean/

Sd

33.17/

7.7

21.57/

3.0

‐‐‐‐‐‐‐ 10.67/

4.46



Abbreviations: SD, standard deviation; BMI, body mass index.

Table 2: Exercise group anthropometric data.

Patients Age

(years)

BMI Neurological

level

Injury

duration

(years)

Medication/

day

1 31



22.34 C3A 8 Baclofen

8pills

2 37



28.35 C4A 17 Baclofen2

pills

3 42 26.12 C4A 11 Baclofen2

pills

4 24 22.4 C6A 5 Baclofen8

pills

5



6



7

49



30



42

26.16



21.85



22.59

C5A



C5B



C4A

13



10



12

Baclofen1

pill

Baclofen3

pills

Baclofen3

pills



Mean/

Sd

36.42/

8.62

24.26/

2.56

‐‐‐‐‐‐‐ 10.85/

3.8

‐‐‐‐‐‐

Abbreviations: SD, standard deviation; BMI, body mass index.

Table 3: Right knee pendulum test results.

Groups

mean/

sd

RI Time

(s)

Fang

(⁰)

Restang

(⁰)

GGbefore



GGafter

0.82/

0.32

0.6/

0.09

8.7/

4.06

9.14/

3.27

88.56/

33.22

117.29/

11.13

61.82/

14.48

69.95/

13.15

EGbefore 0.65/

0.06

10.27/

1.27

117.71/

10.57

77.06/

12.59

EGafter 0.62/

0.08

11.31/

3.36

113.02/

12.75

69.31/

9.11

Abbreviations: SD, standard deviation.

Table 4: Left knee pendulum test results.

Groups

mean/

sd

RI Time

(s)

Fang

(⁰)

Restang

(⁰)

GGbefore



GGafter

0.69/

0.12

0.63/

0.06

7.8/

2.09

7.48/

1.14

78.74/

13.58

106.48/

11.74

52.46/

4.66

66.83/

4.75

EGbefore 0.63/

0.08

9.77/

3.37

105.45/

14.17

65.65/

8.54

EGafter 0.6/

0.08

10.84/

2.83

117.99/

13.59

71.66/

9.88

Abbreviations: SD, standard deviation.

4 DISCUSSION

The pendulum test is fast and easy to apply and in

addiction has an objective assessment.

In this study all patients showed some

improvement in spasticity in both legs after

treatments with NMES, evidenced by at least two

different variables. This improvement may have

occured due to neuromodulation, which happens

through the stimulation of agonist muscle directly to

the quadriceps femuralis and indirectly to the

antagonist (hamstrings) through fibular nerve with

flexion withdrawal reflex.

However in EG group this improvement was

more discret, which may have occurred due to all

individuals in this group take antispastic drug

(baclofen) and most aplenty, so the quadriceps

femuralis were more relaxed than in GG group.

Besides that, in GG group, only one patient takes

baclofen and one pill per day. The baclofen is a

gamma-aminobutyric acid (GABA) agonist that is

used to reduce muscle tone. GABA is an important

inhibitory neurotransmitter in the central nervous

system.

Before treatment EG individuals have already

presented better results when compared to GG

group. However, when results after the treatment are

compared between groups both have similar results

in all variables.

Granat et al (1993) analyzed spasticity through

pendulum test after gait with NMES in patients with

incomplete paraplegia and also showed

improvement in spasticity, observed by RI, like in

the present research.

SpasticityAssessmentthroughPendulumTestinginIndividualswithTetraplegiaUndergoingRehabilitationwith

NeuromuscularElectricalStimulation

5 CONCLUSIONS

NMES and treadmill gait with NMES are effective

treatments for spasticity improvement in individuals

with tetraplegia. However, further studies would be

interesting towards differentiating the baclofen use

and NMES.

ACKNOWLEDGEMENTS

The authors would like to thank CAPES (Ministry of

Education, Brazil).

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