Purpose: This study was conducted to investigate the intrarater and interrater reliability of Kinovea computer program in measuring cervical range of motion in sagittal plane in healthy subjects. Subjects: Sixty-five normal physical therapy intern students participated in this study. Their age ranged from 20 - 24 years with mean (22.42 ± 0.84) and BMI mean (28.60 ± 1.40). Materials and Methods: Digital camera and labtop with installed Kinovea software were used. The cervical ROM of flexion and extension for each participant were measured by Kinovea computer program three times by examiner (B) to detect the intrarater reliability and by three examiners (A, B and C) to detect the interrater reliability. Results: For the intrarater reliability, the ICC between the first and second trials by Rater B for flexion and extension were 0.985 and 0.995. The ICC between the second and third trials were 0.932 and 0.993. The ICC between the first and third trials were 0.920 and 0.986 respectively. For the interrater reliability, the ICC between Rater A & B for flexion and extension were 0.991 and 0.992. The ICC between Rater A & C were 0.988 and 0. 9938. The ICC between Rater B & C were 0.993 and 0.997 respectively. Kinovea computer program had an excellent intrarater and interrater reliability in measuring cervical flexion and extension range of motion at P < 0.05. Conclusion: The Kinovea software program was reliable in both intrarater and interrater reliability in measuring cervical range of motion in sagittal plane.
Cervical disorders are major health problems and an important source of disability. The incidence of cervical problems around the world has a considerable impact on societal health. The clinical manifestations of cervical disorders include pain, headache and decreased range of motion (ROM) which may reduce social participation [
Assessment of ROM is a key concern for the physical therapist when evaluating a patient presenting with cervical disorders. Valid and reliable assessment tools are necessary [
Reliability of ROM measurement tool means the consistency or the repeatability of the same ROM measurements, and expresses their reproducibility or stability only in relation to the time intervals reported [
Kinovea computer program is a software that is able to measure ROM of the joints of the body; the overview function is a summary image of the video. It samples images from the video at regular interval and creates a composite picture where you can see the motion at a glance. The reverse function lets you play the motion back ward [
The most affected cervical ROM in mechanical neck dysfunction are extension and rotation [
The aim of this study was to investigate the intrarater and interrater reliability of Kinovea computer program in measuring cervical ROM in sagittal plane.
This study was conducted in the Faculty of Physical Therapy, Cairo University 2015. Repeated measurement design was used in this study to investigate the intrarater and interrater reliability of Kinovea computer program in measuring active cervical range of motion (ACROM) in sagittal plane. Sixty five healthy normal physical therapy intern students participated in this study, their age ranged from 20-24 years and BMI less than 30 from both genders; they were selected by convenient sampling. Each subject was given full explanation, verbal instructions concerning the purpose and procedure of the current study and the participants signed a consent form with local ethics guidelines prior to participating. All volunteers did not receive monetary rewards or compensation for their time and participation to this study. All volunteers were assessed by the same instruments and the same observers. Ethical approval was obtained from the faculty.
Sixty five normal subjects (physical therapy intern students) with asymptomatic neck pain and ROM deficits.
Age of participants 20 - 24 years.
Both genders.
BMI less than 30.
Previous pain or muscle spasm 3 month before measurements.
Previous history of musculoskeletal or neurological problems of the neck region.
Previous history of cervical trauma, bone pathologies, arthritis, cervical rib, forward head posture or other inflammatory disorders.
Any patient with the diagnosis of spasmodic torticollis was excluded.
1) Digital Camera
CANON A-810 16M 5X HD BK
TFT screen LCD, Screen size 2.7 inch, Max resolution 4608 × 3456 Px. Effective pixels 16 MB Sensor type Super HAD CCD Sensor size 1/2.3-inch Image ratio w:h (4:3), (16:9).
2) Tripod Stand
The digital camera was placed on adjustable tripod stand for standardization. Its height 1.5 meter and the distance between the tripod and the feet of participant was 1.5 meter.
3) Kinovea Software Program
Kinovea is video analysis software dedicated to sport. It targets primarily medical professionals, the coaches and athletes. The supported files are displayed. You can save the videos easily and access it later in need. The video can be analyzed in slow motion so the video can be seen by frame by frame. Lines and arrows can be added on the video with the drawing tool [
4) Computer System
HP PAVILION G6 LAPTOP
Processor CPU Speed 2.5, cache memory 3MB, RAM memory FSB 1333 MHZ, RAM up to 8 GB, hard drive capacity 750, rotational speed 5400RPM, graphic card, HD Bright view LED-backlit with 1366 × 768 screen resolution, size 15.6 inch.
Laptop was used for the Kinovea measurement analysis.
5) Markers
Round markers of 1.5 cm in diameter were glued on special bony land marks.
6) Chest Belt
It was used for fixation and standardization.
The Interrater Reliability
To detect the interrater reliability; three physical therapist examiners (A, B and C) assessed the cervical ROM measurements. They had graduated from the same university; Faculty of Physical Therapy, Cairo University. (Rater A physical therapist specialist with 15 year experience, Rater B physical therapist specialist with 20year experience and Rater C physical therapist with 10 years experience. They had no previous experience with the Kinovea computer program before applying the experiment. Before the beginning of the study, the examiners received three hours of training to adequately manipulate the Kinovea computer program under supervision of highly experienced physical therapist with the Kinovea. In their training sessions, they were taught how to determine which anatomical point of reference which the markers placed on with the Kinovea computer program and they trained for an hour to make sure their method was standardized. Then they measured cervical ROM with the Kinovea computer program as a three trials before starting the Kinovea computer program measurement analysis. All raters were blinded to the results of each other’s reading.
The Intrarater Reliability
To detect the intrarater reliability rater B was used for the intrarater reliability. This rater assessed all subjects on three separate occasions with a 48 hour period separated. The intraclass correlation coefficient (ICC) was calculated between each two trials.
Evaluation Procedure
Physical examination for the neck region was done before the experiment to exclude any disease or neurological deficits that may affect the cervical ROM measurements. History
Inspection from front, lateral and posterior aspects of the neck region.
Palpation for the neck region and related areas.
Special tests (compression-distraction-Adeson) test were applied in doubt cases to confirm and give accurate decision about the participant inclusion.
Group muscle test for neck muscles.
A) Camera Setup
The position of the camera was fixed for standardization all over the experiment and was determined on the basis of the position of the subjects. The position of the tripod on the floor. The position of the subject is marked also and the distance between the participant feet and the tripod was measured by the tape measurement to avoid any changes affect the measurement.
B) Application of Markers
The participant wore 2 elastic headbands to affix head markers. Markers were placed on centered over the external acoustic meatus and the vertex [
Measurement Procedure
Each subject was sitting on a stool close to a wall while maintaining good upright balanced posture, with both feet on the floor, with normal lumbar lordosis, hands on thighs, and with 90 degrees in the hip and knee joints. Each subject was requested to assume a neutral head position, with the purpose of positioning the head’s center of mass in a vertical plane through the atlantooccipital joints with the nose pointing forward in line with the sternum and bellybutton [
Each subject was given full explanation, verbal instruction concerning the purpose and procedure of the study. Markers were placed on the vertex and centered over the external acoustic meatus [
The digital camera was steady to record before position the subject.
Measuring Cervical ROM by Kinovea Computer Program
For the purpose of this study, participants were simply asked to perform maximal (end-range) neck forward flexion with hold 5 seconds then neutral position and lastly extension with hold 5seconds.
Cervical Flexion and Extension
Cervical flexion and extension ROM were measured on a sagittal plane. A marker centered over the external acoustic meatusis the axis of angle between two line segments [
The examiner was sitting behind the camera taking the video.
The examiner asked the participant to flex his neckthen hold 5 seconds at the end of the rangeand return to the neutral position as shown in
From neutral position the examiner asked the participant to extend his neck then hold 5 seconds at the end of the range and return to the neutral position as shown in
The examiner asked the participant to do cervical flexion with chin tuck and extension with chin elevation.
The procedure was repeated three times.
The examiner recorded the results after doing the analysis of each video of each participant by Kinovea computer program.
C) Analysis the Range of Motion by the Kinovea Computer Program as Follow:
The examiner connected the camera with computer.
The examiner apply the analysis for each cervical ROM measurements in sagittal plane.
The procedure was repeated three times then the mean average of the measured angles by Kinovea program were recorded.
The analysis of each participant were saved on computer in a separate file.
1) Descriptive statistics (mean and standard deviation) for measurements of the cervical flexion and extension ROM by Kinovea computer program.
2) Intra-class correlation coefficient (ICC) was used to estimate the intrarater reliability.
3) Intra-class correlation coefficient (ICC) was used to detect the interrater reliability of Kinovea program. The confidence Interval was (CI = 95%) with (P < 0.05) for all tests. For the reliability part of the study, intra and interrater reliability were estimated with the intraclass correlation coefficient (ICC). ICC is a statistic designed to measure the size and direction of the association between two variables [
In this study, 65 subjects (54 male and 11 female) were assigned into one group and as shown in
Intra-rater reliability
To calculate the inter-rater reliability, the mean average of flexion and extension ROM value for each movement were compared between each two trials.
Inter-rater reliability
To calculate the inter-rater reliability, the mean average of flexion and extension ROM value for each movement were compared between each two Raters. Mean and SD of flexion, extension and the ICC between Rater A & B (Flexion ICC 0.991-Extension ICC 0.992) as shown in
Variables | Mean | ±SD |
---|---|---|
Age (yrs) | 22.42 | ±0.84 |
Weight (Kg) | 73.78 | ±6.43 |
Height (cm) | 160.23 | ±6.17 |
BMI (Kg/m2) | 28.60 | ±1.40 |
ICC | 2nd trial (Mean ± SD) | 1st trial (Mean ± SD) | Cervical movement |
---|---|---|---|
0.985 | 59.15 ± 9.154 | 58.83 ± 9.327 | Flexion |
0.995 | 72.68 ± 6.856 | 72.91 ± 6.887 | Extension |
ICC | 3d trial (Mean ± SD) | 2nd trial (Mean ± SD) | Cervical movement |
---|---|---|---|
0.932 | 60.14 ± 8.972 | 58.83 ± 9.327 | Flexion |
0.993 | 72.58 ± 6.899 | 72.68 ± 6.856 | Extension |
ICC | 3d trial (Mean ± SD) | 1st trial (Mean ± SD) | Cervical movement |
---|---|---|---|
0.920 | 60.14 ± 8.972 | 58.83 ± 9.327 | Flexion |
0.986 | 72.58 ± 6.899 | 72.91 ± 6.887 | Extension |
ICC C.I. 95.00% | Rater B (Mean ± SD) | Rater A (Mean ± SD) | Cervical movement |
---|---|---|---|
0.991 (0.985 - 0.994) | 59.37 ± 8.98 | 58.70 ± 9.37 | Flexion |
0.996 (0.994 - 0.998) | 72.72 ± 6.86 | 72.81 ± 6.88 | Extension |
ICC C.I. 95.00% | Rater C (Mean ± SD) | Rater A (Mean ± SD) | Cervical movement |
---|---|---|---|
0.9889 (0.981 - 0.993) | 59.6923 ± 8.95636 | 58.70 ± 9.37 | Flexion |
0.9938 (0.989 - 0.996) | 72.8154 ± 6.88724 | 72.81 ± 6.88 | Extension |
ICC C.I. 95.00% | Rater C (Mean ± SD) | Rater B (Mean ± SD) | Cervical movement |
---|---|---|---|
0.993 (0.989 - 0.996) | 59.6923 ± 8.95 | 59.37 ± 8.98 | Flexion |
0.997 (0.995 - 0.998) | 72.8154 ± 6.88 | 72.72 ± 6.86 | Extension |
This study is the first to examine the Intra-rater and Inter-rater reliability of Kinovea software program in measuring cervical ROM in sagittal plane. Clinical studies have shown that impaired neck rotation, extension, and neck retraction predict high disability [
For a measurement instrument to be useful, the two most important factors that must be established are reliability and validity which affecting the objective measurements [
Kinovea software program has many advantages. It is an accurate method that can be utilized in the establishment of normal values of cervical flexion and extension ROM. It can be utilized in the evaluationprocess in patients with cervical disorders. It is low cost modality. It needs minimal training.
Kinovea software has some disadvantages. It is 2D not 3D program. The therapists who will use it needed to be trained before measuring. There is need to have camera and laptop with installed Kinovea.
Because limited studies are available on the Kinovea, the validity and reliability of this software program were necessary to be evaluated.
Intra-rater reliability
Reliability estimates very important psychometric properties since before an instrument can be considered valid, it needs to be reliable [
Inter-rater reliability
When the cervical flexion and extension ROM were measured by three independent examiners the results were compared, the ICCs were excellent for movements in the sagittal plane and great agreements between the Raters were found. The assessment of the examiner’s skills showed that they were competent (ICC > 0.65) in the use of the method [
Tousignant et al. [
Laflame et al., [
Youdas et al., [
Tucci et al., [
The universal goniometer is the most cheap and available in the markets and clinics. However, the therapist faced many problems during the measurement procedure with the UG, firstly keeping the reference arm of the goniometer stationary while rotating the joint seem to be difficult. It also may be difficult to read the goniometer at end ROM. Removing the goniometer from the joint to read the value can result in unintended movement of the goniometer. [
The systematic review of Williams et al., [
In the current study higher ICCs were estimated in cervical flexion and extension in intra and interrater reliability than any inclinometers, goniometers and any device depending on sensors or magnetic field or gravity affected. The cervical ROM was measured as angles between determined two lines by Kinovea software program. The high ICCs may be attributed good standardization of markers placement and the training sessions of the raters that allowing them to have less errors. The physical therapists need to have accurate, less expensive, easy to use tool without utilizing sensors that may need to be calibrated, to measure cervical ROM.
Other factors may contribute to the results of the current study are the motivation of the subjects, their ability to understand the instructions, and the raters’ behavior, that and instruct the subjects, or the subject’s ability to make and repeat the movement in the same way [
Guzmán et al., [
The results of the current study in agreement of the study done by Abdelreheem et al., [
The results of that study revealed that the Kinovea software program was reliable in both inter- and intra-rater reliability for Wrist joint ROM measurement.
Guzmán et al., [
First, the selected examiners were physiotherapist. Second, the three examiner’s initial preparation (training) with the Kinovea computer program represents strength. Third, the selected participants in the current study were physical therapy intern students so they understand the instructions and the procedure well and performing the procedure in an excellent manner.
Fourth, standardization of the procedures also helped minimize random errors. To achieve this, all participants were stabilized in order to avoid compensation. Also, the given instructions were the same instructions before each measurement for all participants and the environment was identical during all the data collection process: same rooms, same orientation or the participants (facing east), same chairs. All subjects were tested in a standardized seated position using marker placements and non goniometric estimation techniques.
Most reliability studies used only two raters for intertester reliability [
The assessment of validity and reliability of a new ROM measurement tools is so important, as the existing tools have many disadvantages beginning from the size, price, availability ending with the reliability and the ability of physiotherapist to deal with it, so Kinovea software program now become reliable measurement tool that can be used in the physical therapy field [
The reliability might be improved by employing a better standardized procedure and by ensuring that the same instructions were given to the study subjects. The reliability for this measurement method should also be confirmed with a greater number of subjects.
LimitationsThe current study was limited by small sample size.
The Kinovea software program was reliable in both interrater and intrarater reliability in measuring cervical range of motion in sagittal plane.
Further studies with large sample size. Reliability of Kinovea computer program in measuring cervical ROM in transverse and frontal planes. Validity of Kinovea computer program in measuring cervical range of motion in all directions were recommended.
The authors are thankful to all physical therapy intern volunteers from Faculty of Physical Therapy for their critical contribution in the present study.
Shereen H. Elwardany,Wadida H. El-Sayed,Mohammad F. Ali, (2015) Reliability of Kinovea Computer Program in Measuring Cervical Range of Motion in Sagittal Plane. Open Access Library Journal,02,1-10. doi: 10.4236/oalib.1101916