Neck pain by Gwen Jull, Part III
Deficits in the motor (movement) control of the deep and superficial cervical flexor (neck forward bending) muscle have been identified in patients with chronic (long-standing) neck pain. These motor control deficits have been characterized delay in onset of neck flexor activity, most significantly in the deep neck flexors, associated with movement of the upper limb. This delay in onset of contraction of the neck flexor muscles indicates deficit in the automatic motor command for feed-forward control in patients with neck pain. It can be suggested that such a change in the feed-forward response may leave the cervical spine vulnerable to strain from the reactive force resulting from the movement. Altered patterns of cervical flexor muscle activation have also been demonstrated in both low-load cognitive and functional tasks in neck pain patients compared with control subjects. In the cognitive task of craniocervical flexion (head-neck forward bending), reduced deep cervical flexor muscle activity has been demonstrated in those with neck pain, and this has been accompanied by increased activity in the superficial flexors, the sternocleidomastoid and anterior scalene muscle. This pattern suggests possible compensation by the superficial muscles in the presence of impaired deep cervical flexors in neck pain patients.
This altered pattern of muscle activity in the craniocervical flexion test also appears to translate to functional activities, where increased activity of the superficial cervical flexor muscles has been measured in neck pain patients during a simple pencil tapping task. Alterations in the pattern of axioscapular (spine-shoulder baldes) muscle activation were also evident during the performance of this functional task. Neck pain subjects had reduced activity in the trapezius (neck muscle) on their dominant side. This may represent an altered strategy to minimize activation of painful muscles. There was increased activity on the non-dominant side, which rested on the table during the task, and this may be compensation for inhibited, deeper muscles.
The changes in patterns of muscle activity in the neck and shoulder girdle found to date, as well as the delays in onset of neck flexor activity associated with movement of the upper limb, suggest that therapeutic (treatment) exercise should first be directed towards motor (movement) relearning/postural control. Such exercise program should include a focus on activating the deep neck and girdle muscles with low-load and precise exercises in the first instance. Precision is a key and these exercises need to be performed repeatedly in the motor learning process. The muscles' tonic endurance capacity should be trained with low-load holding actions in line with their functional supporting role. Re-education of posture in a neutral upright lumbopelvic (low back and pelvis) position with restoration of the normal lumbar (low back), thoracic (upper back) and cervical (neck) and shoulder girdle position (normal cervical and lumbar lordosis) is an important component of the relearning process of muscle activity in their functional, postural supporting roles. Also, appropriate training of the activation of the muscles in movement patterns of the neck and girdle is frequently required using both specific exercises as well as patient-specific functional tasks. Once the synergistic interaction of the deep and superficial muscles is achieved, co-contraction exercises can be introduced to further enhance muscular stability of the cervicobrachial (neck-shoulder) region. The muscle system can then be loaded to restore strength and endurance to the functional demands of the patient.
Luck LI
Musculoskeletal Physiotherapist
This altered pattern of muscle activity in the craniocervical flexion test also appears to translate to functional activities, where increased activity of the superficial cervical flexor muscles has been measured in neck pain patients during a simple pencil tapping task. Alterations in the pattern of axioscapular (spine-shoulder baldes) muscle activation were also evident during the performance of this functional task. Neck pain subjects had reduced activity in the trapezius (neck muscle) on their dominant side. This may represent an altered strategy to minimize activation of painful muscles. There was increased activity on the non-dominant side, which rested on the table during the task, and this may be compensation for inhibited, deeper muscles.
The changes in patterns of muscle activity in the neck and shoulder girdle found to date, as well as the delays in onset of neck flexor activity associated with movement of the upper limb, suggest that therapeutic (treatment) exercise should first be directed towards motor (movement) relearning/postural control. Such exercise program should include a focus on activating the deep neck and girdle muscles with low-load and precise exercises in the first instance. Precision is a key and these exercises need to be performed repeatedly in the motor learning process. The muscles' tonic endurance capacity should be trained with low-load holding actions in line with their functional supporting role. Re-education of posture in a neutral upright lumbopelvic (low back and pelvis) position with restoration of the normal lumbar (low back), thoracic (upper back) and cervical (neck) and shoulder girdle position (normal cervical and lumbar lordosis) is an important component of the relearning process of muscle activity in their functional, postural supporting roles. Also, appropriate training of the activation of the muscles in movement patterns of the neck and girdle is frequently required using both specific exercises as well as patient-specific functional tasks. Once the synergistic interaction of the deep and superficial muscles is achieved, co-contraction exercises can be introduced to further enhance muscular stability of the cervicobrachial (neck-shoulder) region. The muscle system can then be loaded to restore strength and endurance to the functional demands of the patient.
Luck LI
Musculoskeletal Physiotherapist