Investigating the Effectiveness of Graded Motor Imagery Training in Children With Obstetric Brachial Plexus Injury

The Modified Mallet Classification is a valid and reliable scale frequently used in the literature to determine the functional status of the upper extremity in individuals with brachial plexus injuries. Rather than assessing the functions of individual muscles, this classification system evaluates the global functional characteristics of the affected upper extremity. It assesses five movements: global abduction, global external rotation, hand-to-neck, hand-to-mouth, and hand-to-spine. Each movement is scored from 1 to 5 according to the position achieved and the quality of movement. The total score ranges from 5 to 25, with higher scores indicating better upper extremity function.

The Active Movement Scale was developed by the Brachial Plexus Clinic at The Hospital for Sick Children in Toronto. In children with obstetric brachial plexus injury, the affected upper extremity is evaluated across 15 joint movements extending from the shoulder to the fingers. Each movement is initially assessed with gravity eliminated. If full movement is achieved in the gravity-eliminated position, the movement is subsequently evaluated against gravity. Each movement is scored separately from 0 to 7, with higher scores indicating better active movement performance.

Range of motion (ROM) was assessed using a universal goniometer to identify movement limitations in the upper-extremity joints. Measurements were performed according to standard goniometric measurement principles and recorded in degrees. Active range of motion of the shoulder, elbow, forearm, and wrist joints of the affected upper extremity was evaluated. The assessed movements included shoulder flexion, extension, abduction, internal rotation, and external rotation; elbow flexion and extension; forearm supination and pronation; and wrist flexion and extension. During the assessment, the participants' starting positions and the placement of the goniometer axis, stationary arm, and moving arm were standardized according to established measurement procedures. Care was taken to prevent compensatory movements originating from the trunk, scapula, shoulder, and forearm.

The Movement Imagery Questionnaire for Children was used to assess the child's motor imagery ability. The questionnaire evaluates the ability to mentally imagine movements using three imagery modalities: internal visual imagery, external visual imagery and kinesthetic imagery. The child is asked to imagine specific movements and then rate how easy or difficult the imagery experience was. Each item is scored on a 7-point scale, where lower scores indicate more difficult imagery and higher scores indicate easier and better imagery ability. Subscale scores are calculated for internal visual imagery, external visual imagery and kinesthetic imagery. Higher subscale and total scores indicate better motor imagery ability.

The Kinesthetic and Visual Imagery Questionnaire-20 was used to evaluate visual and kinesthetic motor imagery ability. Participants are asked to perform or assume specific movement positions and then mentally imagine the same movement. For each item, the clarity of the visual image and the intensity of the kinesthetic sensation are rated separately. Visual imagery is scored according to how clear the imagined image is, and kinesthetic imagery is scored according to how strongly the movement sensation is felt. Each item is scored on a 5-point scale. Higher visual imagery scores indicate clearer mental images, and higher kinesthetic imagery scores indicate stronger kinesthetic sensations. Higher total scores indicate better motor imagery ability.

Raimondi Hand Score was used to evaluate hand function of the affected upper extremity. The classification assesses functional hand use, including grasp ability, finger flexion and extension, wrist movement, thumb use and forearm rotation. The score ranges from 0 to 5. A score of 0 indicates complete paralysis or absence of grasp, while higher scores indicate progressively better hand and finger function. A score of 5 represents strong finger flexion and extension, full pronation and supination, and good use of the thumb and intrinsic hand muscles. Higher scores indicate better hand function.

Gilbert-Raimondi Elbow Function Scale was used to assess elbow movements. The scale comprises three components: the degree of active elbow flexion achieved, elbow extension strength, and extension deficit. During the assessment, elbow flexion and extension movements were explained to the participant, who was then instructed to perform them actively. The elbow extension deficit was also measured in degrees. Flexion was scored as 1 when there was no movement or only muscle contraction, 2 for incomplete movement, and 3 for complete movement. Extension was scored as 0 when no movement was present, 1 when extension was weak, and 2 when it was good. The extension deficit was scored as 0 for 0-30°, -1 for 30-50°, and -2 for deficits greater than 50°. Based on the total score, elbow function was classified as poor for scores of 0-1, moderate for scores of 2-3, and good for scores of 4-5. Higher scores indicate better elbow function.

Gilbert Shoulder Function Rating System was used to assess shoulder function and the degree of recovery of shoulder movements in participants with obstetric brachial plexus injury (OBPI). This system grades shoulder function based on shoulder abduction and active external rotation. During the assessment, participants were instructed to actively perform shoulder abduction and external rotation. Scores ranged from 0 to 5 based on the degree of shoulder abduction and active external rotation, with higher scores indicating better shoulder function.

The Quality of Upper Extremity Skills Test (QUEST) is a performance-based assessment tool developed to evaluate the quality of upper-extremity movement and manual skills in children. During the assessment, participants were observed in accordance with the standardized test instructions. Dissociated and controlled movement skills were assessed in the dissociated movements domain; the ability to grasp and release objects in the grasp domain; the capacity to bear weight through the upper extremity in the weight-bearing domain; and protective upper-extremity responses to loss of balance or postural changes in the protective extension domain. Scoring was performed according to the formulas and standardized instructions provided in the scoring manual. Each domain score and the overall QUEST score range from 0 to 100, with higher scores indicating better quality of upper-extremity movement and functional ability.

The Box and Block Test was used to assess gross manual dexterity and functional hand performance. The test was administered using a standard box divided into two compartments by a partition and equally sized wooden blocks. During the assessment, the participant was seated at a table, and the box was positioned so that the compartment containing the blocks was on the side of the extremity being tested. Before the test, the instructions were explained to the participant, and a brief practice trial was provided to ensure comprehension. The participant was then instructed to transfer the blocks one at a time from one compartment to the other as quickly as possible for 60 seconds. At the end of the test, the number of blocks transferred to the opposite compartment was recorded. A higher score indicated better gross manual dexterity and functional performance of the upper extremity.

Handgrip strength was assessed using a Jamar hydraulic hand dynamometer. Measurements were performed in the standard testing position recommended by the American Society of Hand Therapists. Participants were seated with their hips and knees flexed to approximately 90°, the shoulder adducted, the forearm in a neutral position, the elbow flexed to 90°, and the wrist positioned at 0-30° of extension. Participants were instructed to grip the dynamometer and squeeze with their maximum possible force and were verbally encouraged during each measurement. Three measurements were performed for the affected upper extremity, with brief rest intervals between trials. The mean of the three measurements was calculated and recorded in kilograms. Higher values indicate greater handgrip strength.

The T-Shirt Donning and Doffing Test was administered to assess upper-extremity functional performance and movement ability during activities of daily living. The test was performed using a standard T-shirt, with the participant standing 30 cm behind a table. Upon receiving the command, the participant was instructed to put on the T-shirt, take it off, and place it back on the table. The test ended when the removed T-shirt touched the table, and the elapsed time was recorded in seconds. The test was repeated three times, and the mean of the three trials was used in the analysis. A shorter completion time indicates better upper-extremity functional performance.

Proprioceptive accuracy was assessed at the shoulder and elbow using an active joint position reproduction test with a digital inclinometer. During testing, the participant's vision was occluded. For shoulder abduction, the examiner passively moved the affected arm from the 0° starting position to the target angles of 60° and 90°. Each target position was maintained for 5 seconds to allow the participant to perceive and learn the position, after which the arm was returned to the starting position. The participant was then asked to actively reproduce the target angle. The same procedure was performed for elbow flexion at target angles of 60°, and 90°. Three trials were completed at each target angle. The absolute angular error between the target angle and the actively reproduced angle was calculated for each trial, and the mean of the three trials was recorded in degrees.

The Timed Up and Go Test is a simple, practical, and rapid performance-based test used to assess functional mobility and dynamic balance. The child is instructed to stand up from a standard chair with a backrest and armrests, walk a predetermined distance of 3 meters as quickly and safely as possible without running, turn around without touching or receiving support from any object, walk back to the chair, and return to a seated position. The time required to complete the test is recorded in seconds. Lower completion times indicate better functional mobility and dynamic balance.

The Timed Up and Down Stairs Test is a valid and reliable performance-based test used to assess functional mobility and dynamic balance. The test begins with the child standing 30 cm from the bottom of a 10-step staircase. On command, the child is instructed to ascend the stairs as quickly and safely as possible, turn around immediately after reaching the top step without pausing, and descend the stairs. Timing begins with the command to start and ends when the child steps off the lowest step and places both feet on the floor. The time required to complete the test is recorded in seconds. Lower completion times indicate better functional mobility and dynamic balance.

The Functional Reach Test is an easily administered, performance-based assessment used to evaluate dynamic balance and postural stability. It measures the maximum distance an individual can reach forward in the horizontal plane while maintaining a fixed base of support in standing. The participant stands beside, but does not touch, the measurement surface and raises the arm to 90° of shoulder flexion. The initial position of the tip of the third finger is recorded. The participant is then instructed to reach forward as far as possible without moving the feet, taking a step, touching the measurement surface, or losing balance. The final position of the tip of the third finger is recorded. The functional reach distance is calculated as the difference between the initial and final positions and is reported in centimeters. Greater distances indicate better dynamic balance and postural stability.

PedsQL 4.0 was used to assess the participants' health-related quality of life. The scale consists of 23 items and evaluates four core domains: physical functioning, emotional functioning, social functioning, and school functioning. Subscale scores are calculated by averaging the corresponding item scores, whereas the total scale score is calculated by averaging all item scores. Items are rated on a 5-point Likert scale and reverse-scored and linearly transformed to a 0-100 scale. Higher scores indicate better health-related quality of life.