Background and Purpose: Rock climbing has been a popular sport in recent years. Rock climbing includes various open-chain and closed-chain arm movements. Overhead reaching and pull-up are the basic rock climbing elements heavily involving upper extremities. Different inclination of the wall and terrain also demand sufficient range of motion and strength of the trunk. Generally overhead reaching and arm elevation may have similar shoulder kinematics, including scapular upward rotation, posterior tilt and external rotation. Arm elevation usually is accompanied with thoracic extension and unilateral lateral flexion and rotation. During pull-up, the scapula rotates downward and externally and tilts anterior. The prevalence of shoulder injuries are about 17%, the second most common among rock climbing injuries. In the shoulder injuries, shoulder labrum lesions and shoulder impingement are the most common. Previous studies have shown that individuals with shoulder impingement syndrome have shown decreased upward and externally rotation during arm elevation, and have limited thoracic extension range of motion and greater kyphotic posture. However, a previous study found no difference in the scapular kinematics and scapular muscle activation during pull-up in rock climbers with shoulder pain and healthy climbers. The non-significant finding may be due to that the pure pull-up may not mimic climbing tasks, in which the shoulder and trunk need to adapt different inclination of the wall. Therefore, the purpose of this study is to investigate the kinematics and muscle activation of the thoracic spine and shoulder in rock climbers with shoulder pain during climbing tasks with different reaching angles. Methods: Thirty sport climbers with shoulder pain and 30 healthy climbers matched with gender, age, and dominant hand will be recruited in this study. Testing tasks will include arm elevation in the scapular plane, overhead reaching to the target 15° backward to the frontal plane, pull-up with overhead reaching forward and backward. Thoracic and shoulder kinematics will be collected using an electromagnetic tracking system. The upper trapezius, lower trapezius, serratus anterior, latissimus dorsi, and erector spinae were collected with surface electromyography (EMG). A two-way mixed ANOVA will be used to determine differences between groups in the kinematics and EMG measures at the different arm elevation angles for the testing tasks.
Study Type
OBSERVATIONAL
Enrollment
37
arm elevation in the scapular plane, overhead reaching to the target 15° backward to the frontal plane, pull-up with overhead reaching forward and backward.
National Yang Ming Chiao Tung University
Taipei, Taiwan
Shoulder kinematics during arm elevation
Scapular kinematics, including anterior/posterior tilt, upward/downward rotation, and internal/external rotation in scapular plane elevation at 30°, 60°, 90°, and 120°, and will be described with degree (°).
Time frame: Immediately during the experiment
Thoracic kinematics during arm elevation
Thoracic kinematics, including flexion, extension, side flexion and rotation in arm elevation at 30°, 60°, 90°, and 120°, and will be described with degree (°).
Time frame: Immediately during the experiment
Shoulder kinematics during pull-up with overhead reaching forward and backward
Scapular kinematics, including anterior/posterior tilt, upward/downward rotation, and internal/external rotation, and will be described with degree (°).
Time frame: Immediately during the experiment
Thoracic kinematics during pull-up with overhead reaching forward and backward
Thoracic kinematics, including flexion, extension, side flexion and rotation
Time frame: Immediately during the experiment
Scapular muscles activation during arm elevation
The root mean square of electromyography (EMG) data of the upper trapezius, lower trapezius, serratus anterior, and latissimus dorsi will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %) and calculated over three 30° increments of motion during arm elevation from 30° to 120°, including 30° - 60°, 60° - 90°, and 90° - 120°.
Time frame: Immediately during the experiment
Trunk muscle activation during arm elevation
The root mean square of electromyography (EMG) data of the erector spinae will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %) and calculated over three 30° increments of motion during arm elevation from 30° to 120°, including 30° - 60°, 60° - 90°, and 90° - 120°.
Time frame: Immediately during the experiment
Scapular muscles activation during pull-up with overhead reaching forward and backward
The root mean square of electromyography (EMG) data of the upper trapezius, lower trapezius, serratus anterior, and latissimus dorsi will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %)
Time frame: Immediately during the experiment
Trunk muscle activation during overhead reaching forward and backward.
The root mean square of electromyography (EMG) data of the erector spinae will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %)
Time frame: Immediately during the experiment
Thoracic mobility
Range of motion of thoracic spine, described with degree (°).
Time frame: Immediately during the experiment
Thoracic kyphosis angle
measured by inclinometers, described with degree (°).
Time frame: Immediately during the experiment
Muscle length of pectoralis major
In a supine position with hands behind the head. A positive (+) indicates muscle tightness, when the elbows cannot touch the testing surface.
Time frame: Immediately during the experiment
Muscle length of pectoralis minor
In a supine position, the distance between acromion and testing surface, described with cm.
Time frame: Immediately during the experiment
Muscle length of latissimus dorsi
shoulder flexion range of motion in a hook-lying position, described with degree (°)
Time frame: Immediately during the experiment
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.