The Acute Effect of Proprioceptive Neuromuscular Facilitation on Cervical Range of Motion, Strength and Proprioception
Phase: NA
Conditions: Proprioception, Neck
Sponsor: Yeditepe University

 
STUDY PROTOCOL AND STATISTICAL ANALYSIS 
PLAN 
 
The Acute Influence of Proprioceptive Neuromuscular 
Facilitation on Cervical Proprioception and Range of Motion. 
 
 
 
 
 
Date: 25/02/2019 
NCT Number:  
NCT04045106  
 
 
 
Prepared by: 
Mohammad AL-Jallad 
 
ISTANBUL/TURKEY 
 
 

Study Summery 
Title 
The acute influence of Proprioceptive neuromuscular facilitation on 
cervical proprioception and range of motion. 
Methodology Randomized, controlled trial, double blinded study 
Study 
Duration 
The estimated time for participants recruitment, screening and protocol 
implantation is 20 days 
Study 
Location 
University Labs 
Subjects 
120 healthy subjects randomized to 3 arms: 2 treatment and 1 control 
Inclusion criteria: To determine if a participant is healthy a score of 5 or 
less on the neck disability index will be used, no history of cervical trauma, 
rheumatic diseases, whiplash syndrome, no history of surgeries to the neck, 
face and shoulders, no history of cancer, no history of systemic diseases, 
age of 18 or above and able to understand and follow instructions. 
Assessment 
Cervical Proprioception using cervical range of motion (CROM) 
instrument, Active Range of motion (AROM) using CROM instrument, 
Muscle strength using a myometer device. 
Intervention 
PNF Pattern: Dynamic of reversals technique, PNF stretching: contract-
relax-antagonist contract (CRAC) technique, control group: ineffective 
passive ROM. 
 
Statistical 
Methodology 
Statistical analyses will be performed using SPSS software version 25. 
Descriptive analyses will be presented using means and standard deviations 
for continuous data and frequencies and percentages for categorical data. 
The variables investigated using Kolmogorov Smirnov test to determine 
whether or not they are normally distributed. Since the variables are 
normally distributed, ANOVA will be used to compare the means of the 
groups., Levene test will be used to assess homogeneity of variances. When 
an overall significance will be observed, pairwise post-hoc tests will be 
performed using Tukey’s test. Since the variables are not normally 
distributed Kruskal-Wallis test will be used to compare the groups. The 
Mann-Whitney U test will be performed to test the significance of pairwise 
differences using Bonferroni correction to adjust for multiple comparisons.  
Since the variables are normally distributed, the effect of time change in 
measurements will be investigated by Repeated Measures ANOVA test. 
Greenhouse-Geisser correction will be used when sphericity assumption is 
violated. Since the variables are not normally distributed Friedman test will 
be used. The Wilcoxon test will be performed to test the significance of 
pairwise differences using Bonferroni correction to adjust for multiple 
comparisons. A 5% type-I error level was used to infer a statistical 
significance. 
 
 
 
 

Background information: 
 
Proprioception is the ability to sense the information raised from the musculoskeletal system 
regarding the movement and position of body part in space, there are many types of 
proprioceptors in the body such as skin, joint capsule and connective tissue but the largest 
contributors to joint position sense are the intermuscular receptors which are golgi tendon 
organs and muscle spindles. 
The cervical region has high density of muscle spindles that allow a great precision of 
movement while also providing adequate proprioceptive information to control head position 
and movement and for eye-head coordination.  
Proprioceptive neuromuscular facilitation (PNF) are synergistic pattern of movement with the 
emphasis of facilitating normal movement, the proposed mechanism for some types of PNF 
that they are reliant on the facilitation of golgi tendon organs and muscle spindles which are 
responsible for two reflexes 1. autogenic inhibition 2. Reciprocal inhibition, although there is 
conflicting evidence regarding the mechanisms of PNF the beneficial effects are well 
established on many conditions like range of motion, neuromuscular functions, lymphedema 
and many more. 
Most of the studies that tested PNF on the cervical region measured range of motion, 
flexibility and strength. Studies conducted to influence cervical proprioception used multiple 
interventions such as head relocation practice, eye/head coordination exercises, muscle 
vibration, mental training, strength and motor control exercises.  
Due to the importance of cervical proprioception and the lack of studies in literature, the 
Purpose of this study is to investigate the acute influence of proprioceptive neuromuscular 
facilitation on cervical proprioception, range of motion and strength. 
Study Design: This is a double-blinded randomized controlled trial. Participants were not 
aware of their assigned group, also the assessor was blinded to group allocation. 
Sample Size: The sample size was calculated by using G*Power 3.1.7 for Windows 
(G*Power©, University of Dusseldorf, Germany), by using f family test ANOVA repeated 
measures and between factors, with statistical power of 0.80 (1-B error Probability) and alpha 
error level probability of 0.05 and effect size of 0.25 with number of measurements being 2, 
which total to 120 participants. 
Participants will be recruited from university campus by directly asking students from classes 
if they can volunteer by explaining that the trial will involve the cervical region, also 
mentioned that is one-time session that can take up to an hour. Participants then will be 
handed consent forms that included more details about the trial. 
 
 
 
 

Inclusion Criteria: 
• Neck disability index score of 5 or less 
• Able to understand and follow instructions 
• Above 18 years old 
Exclusion Criteria: 
• Cervical trauma 
• History of cervical inter-vertebral disc pathology 
• Rheumatic diseases 
• Whiplash syndrome 
• History of surgeries to the neck, face and shoulders 
• History of systemic diseases 
Randomization and Procedures Randomization done by a person external to the study. 
Participants that signed the consent form and meet the inclusion criteria were assigned a 
number which corresponded to one of the three groups. Participants were asked to enter a 
room where the assessor preformed the first measurements, then participants were asked to 
go to a separate room where the treatment methods took place. The therapist corresponded 
the number of the participant to the randomization sheet and applied the assigned treatment. 
After that participants were asked to go back to the first room for the second measurement. 
Participants were asked not to make a comment to the assessor but they can direct any 
question to the therapist. 
ASSESSMENT METHODS  
Cervical Proprioception: The cervical proprioception will be done using cervical range of 
motion instrument (CROM, Performance Attainment Associates, Lindstrom, MN, USA) 
using the joint position accuracy method of proprioception assessment, the device is made of 
a plastic frame that rest over the head, nose and ears, with a strap to secure it, it has three 
inclinometers attached to the frame, one in the sagittal plane, the second in the frontal plane 
and the third in the horizontal plane, which makes able to measure all 6 directions of 
movement. This instrument was reliable and valid to assess cervical proprioception, the 
chosen target angle is 30 degrees.  
Cervical proprioception was done for flexion, extension, right side bending, left side bending, 
right and left rotation.  
Participants will be asked to sit and put on the CROM instrument, then they will be instructed 
to start moving their head to one of directions then the assessor will stop them at 30 degrees 
and tell them to feel the amount of movement and muscle tension, this will be repeated 3 
times as a reference, then they will be asked to do the movement with the eyes closed until 
they reach the target angle, this will be repeated for 3 times, this will be done for each 
direction and the assessor will record the results.  
 
 
 

Range of Motion and Muscle Strength Measurement: 
Active Range of motion (AROM) will be measured using CROM instrument, the validity and 
reliability of CROM to assess ROM is well documented in the literature, AROM was taken 
for all movement directions. 
Muscle strength will be measured using a myometer device (microFET2™ Hoggan Health 
Industries, Inc, West Jordan, Utah), cervical flexors, extensors, right and left rotators and 
right and left lateral flexors muscle strength will be measured. 
Intervention Methods  
As discussed earlier, participants were allocated to three groups, these are PNF pattern, PNF 
stretching and a control group.  
PNF patterns will be performed using Dynamic of reversals technique which is characterized 
as active motion alternating from one direction (agonist) to the opposite (antagonist) without 
relaxing.  
The cervical patterns consisted of 1- Cervical flexion with right rotation followed by 
extension with left rotation. 2- Cervical flexion with left rotation followed by extension with 
right rotation.  
The participants will be asked to sit on a chair, the therapist will performe the pattern of 
movement himself then passively apply the pattern on the participant then ask the participant 
to perform the pattern, and the therapist will observe and correct the movement if it was done 
improperly. then participants will be told that the therapist will resist their movement, they 
will be instructed to keep breathing normally and to report any discomfort and/or pain. After 
mastering the pattern, the therapist will place one hand on the participant’s mandibular and 
the other hand approximately between parietal and occipital bones to apply resistance 
throughout the ROM, each pattern will be performed for 3 sets of 10 repetitions with 1-2-
minute rest between sets. 
 PNF stretching will be done using contract-relax-antagonist contract (CRAC) technique for 
cervical flexors, extensors, right and left lateral flexors, right rotators and left rotators. This 
will be done for 6 repetitions with hold for 6 seconds in a position of stretch and submaximal 
isometric contraction for 6 seconds, 1-2-minute rest will be given before changing the target 
muscle group.  
Control Participants allocated to the control group will receive ineffective passive ROM for 
10 repetitions for flexion, extension, right and left side bending and right and left rotation, it 
will be done from neutral position to the limit of motion without causing any stretch to the 
muscle. 
 
 
 
 
 

Statistical Analysis Plan:  
Statistical analyses will be performed using SPSS software version 25. Descriptive analyses 
will be presented using means and standard deviations for continuous data and frequencies 
and percentages for categorical data. The variables investigated using Kolmogorov Smirnov 
test to determine whether or not they are normally distributed. Since the variables are 
normally distributed, ANOVA will be used to compare the means of the groups., Levene test 
will be used to assess homogeneity of variances. When an overall significance will be 
observed, pairwise post-hoc tests will be performed using Tukey’s test. Since the variables 
are not normally distributed Kruskal-Wallis test will be used to compare the groups. The 
Mann-Whitney U test will be performed to test the significance of pairwise differences using 
Bonferroni correction to adjust for multiple comparisons. Since the variables are normally 
distributed, the effect of time change in measurements will be investigated by Repeated 
Measures ANOVA test. Greenhouse-Geisser correction will be used when sphericity 
assumption is violated. Since the variables are not normally distributed Friedman test will be 
used. The Wilcoxon test will be performed to test the significance of pairwise differences 
using Bonferroni correction to adjust for multiple comparisons. A 5% type-I error level was 
used to infer a statistical significance.