Reliability and Validity of Hand Dynamometer Trunk Muscle Strength Measurements in Patients With AIS

Adolescent idiopathic scoliosis (AIS) is a three-dimensional complex deformity of the spine characterized by lateral deviation of 10 degrees or more in the frontal plane, rotation in the transverse plane and hypokyphosis in the sagittal plane. It has been reported that in the presence of scoliosis, there is a change in muscle strength of people compared to their healthy peers due to the deterioration of their postural balance. There are many studies in the literature that evaluate the muscle strength of cases diagnosed with scoliosis with objective devices. Among these objective devices, reliability studies on hand dynamometry devices, which are easy to use, portable and cheaper than other devices, have been conducted for different populations. However, no reliability study of the handheld dynamometer device in patients with AIS has been found in the literature. Therefore, the aim of our study is to study the intra-rater and inter-rater reliability and validity of the trunk flexion, extension and lateral flexion muscle strengths of the hand dynamometer device in cases with AIS, which are known to have changes in muscle strength compared to their peers as a result of the change in spinal alignment. After obtaining the demographic information of the cases that meet the inclusion criteria within the scope of the study, the isometric muscle strength of the trunk flexor, extensor and right-left lateral flexor muscles will be evaluated by two different evaluators using a Lafayette hand dynamometer. To avoid systematic error, each participant will perform the isometric handheld dynamometer protocol in a random testing order. In order to determine interobserver reliability, on the first day of the test, the same hand dynamometer protocol will be applied to each participant by two different evaluators, after a 1-hour rest to prevent fatigue. To determine intraobserver reliability and compliance, participants will be re-evaluated by the same researchers at the same protocol, place and day period, 1 week apart to prevent learning effects. This study will reveal the intraobserver and interobserver reliability and validity of the handheld dynamometer device, which can be used in the evaluation of trunk muscle strength for clinicians working with AIS.

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Key information

Conditions

Scoliosis; Adolescence Adolescent Idiopathic Scoliosis Behavior Bone Diseases Motor Activity Musculoskeletal Diseases Scoliosis Spinal Curvatures Spinal Diseases

Age range

10 year–18 year

Sex eligibility

All sexes

Study type

Observational

Primary location

İrem Kurt

Istanbul, 34147, Turkey (Türkiye)

About this study

Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional complex deformity of the spine characterized by lateral deviation of 10 degrees or more in the frontal plane, rotation in the transverse plane and hypokyphosis in the sagittal plane, and is an important public health problem with a global prevalence of 0.47-5.2%. Muscle strength is an important factor in maintaining postural balance in AIS, and it is observed that both clinicians and researchers evaluate the muscle strength of cases with AIS using different objective devices. Objective muscle strength assessment methods include electromyography, hand dynamometry and isokinetic dynamometry. Electromyography devices and isokinetic dynamometers are expensive and their use in the clinic is limited because they are not easily portable. Therefore, it has been shown to be a valid and reliable method to evaluate trunk muscle strength in different populations and pathologies such as healthy adults, healthy athletic individuals, chronic low back pain or hemiplegic patients; The handheld dynamometer device, which has the advantage of being cheaper and more portable than other devices, appears as a suitable option for clinicians to evaluate trunk isometric muscle strength. No reliability studies of hand dynamometer devices have been found in the AIS population. Therefore, our aim in the study is to study the intra-observer and inter-observer reliability and validity of the trunk flexion, extension and lateral flexion muscle strengths of the hand dynamometer device in patients with AIS, who are known to have changes in muscle strength compared to their peers as a result of the change in spinal alignment. This study will reveal the validity of the hand dynamometer device that can be used in the evaluation of trunk muscle strength for clinicians working with AIS.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Being between the ages of 10-18
Having been diagnosed with Adolescent Idiopathic Scoliosis by an orthopedic specialist
Ability to understand instructions
Volunteering to participate in the study

Exclusion criteria

History of traumatic trunk or pelvic injury
History of acute, subacute or chronic low back pain or neurological disease
Having had spinal surgery
Participating in heavy physical activity at least one day before the test days
Having experienced any acute situation that could affect muscle strength between the two tests (within 7 days)

Treatment and study plan

Primary outcomes

Isometric trunk flexor strength

Time frame: Baseline (All rater), after 1 hour (Rater 1) and 1 week (Rater 1)

Isometric trunk flexor strength, two different test positions were adapted based on current literature. The first position will be measured on the back at 0 degrees of extension, with the knees straight. The dynamometer will be placed below the suprasternal notch of the sternum. Participants will be instructed to place their hand on the opposite acromion. To prevent pelvic rotation, participants will be fixed with the help of a belt from the anterior superior iliac spine and 10 cm above the lateral malleolus. The second position will be measured on the back in a 30 degree flexion position with the knees straight. The dynamometer will be placed below the suprasternal notch of the sternum. Participants will be instructed to place their hand on the opposite acromion. To prevent pelvic rotation, participants will be fixed with the help of a belt from the anterior superior iliac spine and 10 cm above the lateral malleolus.
Isometric trunk extension strength

Time frame: Baseline (All rater), after 1 hour (Rater 1) and 1 week (Rater 1)

Isometric trunk extension strength, two different test positions were adapted based on current literature. The first position will be measured face down in 0 degree extension position. The dynamometer will be placed at the height T4. Participants will be instructed to place their hands on their foreheads. Participants will be fixed with the help of a belt from the posterior superior iliac spine and 10 cm above the lateral malleolus to prevent pelvic rotation. The second position will be measured face down in a 30 degree flexion position. The dynamometer will be placed at the height T4. Participants will be instructed to place their hands on their foreheads. Participants will be fixed with the help of a belt from the posterior superior iliac spine and 10 cm above the lateral malleolus to prevent pelvic rotation.
Isometric trunk lateral flexion strength

Time frame: Baseline (All rater), after 1 hour (Rater 1) and 1 week (Rater 1)

Isometric trunk lateral flexion strength will be measured in the sitting position. Participants will sit on a chair with their feet not touching the ground and their hips in 90° flexion, and the participant will be fixed with the help of a strap. The dynamometer will be placed at shoulder level. Participants will be instructed to place their hand on the opposite acromion. Trials in which excessive motion (a detectable amount of movement or rotation in the transverse plane) occurs will be rejected and measured as.

Sponsors and collaborators

Lead sponsor

Istanbul University - Cerrahpasa

Other

Registry information

Official study title

Intra-rater and Inter-rater Reliability and Validity of Hand Dynamometer Trunk Flexor, Extensor and Lateral Flexor Muscle Strength Measurements in Patients With Adolescent Idiopathic Scoliosis

Important dates

Study start: 2024
Primary completion: 2026
Study completion: 2026
First posted: May 16, 2024
Registry last updated: Jul 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed