Muscle imbalances in the neck and shoulders are very common and can cause a multitude of problems, including chronic neck pain. Traditionally, when we think of muscle imbalances we think of syndromes in which some muscles become inhibited and weak and others become short and stiff. Chronic muscle imbalance can bring changes in soft-tissues, which may cause faulty movement patterns and lead to long-term dysfunction. Such imbalances can eventually cause pain and inflammation in the joints and disc sin the neck by putting them under excessive mechanical load and strain. The cause of such patterns,generally speaking, is due to the stationary postures and/or the repetitive tasks we engage in.
Conversely, proper muscle balance is achieved by creating a uniformity of muscle length and/or strength between the agonist and the antagonist muscle groups.
the antagonist in that scenario.]
In the cervical spine (neck), the muscle imbalance that we want to focus on are the cervical flexors, pectoralis muscle group, suboccipital, upper trapezius, rhomboids, and the lower trapezius muscles. See the diagram below taken from Human Kinetics in 2010.
In this example, we see something called the Upper Crossed Syndrome, where weakness associated with the cervical flexors is linked with weakness in the rhomboids and lower trapezius muscle groups. Additionally,tightness in the pectoralis muscles is linked with tightness and shortening in the suboccipital muscles as well as the upper trapezius muscles. This is a typical pattern we seen in many clients. Kinesiologists and Bio-mechanistshave given the term Phasic muscles to muscles that get weak, lengthened and inhibited. Muscles that get facilitated, over-reactive and tight (or more accurately shortened) are termed Postural muscles. It is important to keep these classifications of musclesseparate in our exercise regimes in order to make sure we are stretching and strengthening the correct muscle groups. Of interest, other Postural and Phasic muscles are depicted in this list below.
Phasic = inhibited, weak and lengthened
This Upper Crossed Syndrome is typical of patients with neck pain and can lead to clinical issues such as forward head posture and increased craniovertebral angle. So, how do we develop these muscle imbalances? Are we born with them or do we develop them? Well, to answer those questions let’s take a journey.They actually do develop slowly overtime with the repetitive use of poor posture. Take the examplebelow, text neck. Because of the rising popularity of media devices such as smartphones and computers, frequent users often exhibit this horrible posture (see below).They stand with their necks hanging and resting on the ligaments of the cervical spine. The load on the small discs and facet joints of the cervical spinal segmentscan exceed an additional 60lb pounds of force on those joints. After putting your head in this position repetitively, overtime, the muscle imbalances will begin to develop. We start see that weakness develops in the cervical flexors, rhomboids and lower trapezius muscle groups. Additionally, shortening develops in the pectoralis muscles. This pattern of imbalance creates joint dysfunction, particularly at the atlanto-occipital joint, C4-C5 segment, cervicothoracic joint, even the glenohumeral(shoulder) joint, and T4-T5 segment.
When you come in to physical therapy we will evaluate this postural position using a technique called craniovertebral angle, where a smaller angle represents a worsening of the forward head position. A high level of smartphone addiction reduces the craniovertebral angle and increases a dysfunction called scapular dyskinesis. Scapular dyskinesisis a general term meaning a deviation of the normal resting or active position of the scapula (shoulder blade)during shoulder movement. (see picture at the bottom of the article). Therefore, the smartphone addiction level should be assessed in all patients with neck and shoulder pain to plan appropriate management. Moreover, the craniovertebral angle is a measurement of a horizontal line passing through the C7 spinous process and a line joining the midpoint of the tragus of the ear (seen pictures below).Measurement of craniovertebral angle, is a common method in assessing the degree of forward head posture.
Apatient’s understanding of his or her craniovertebral angle and help them avoid repetitive poor neck positions with their activity of daily living. In order to make changes in a patients craniovertebral anglein chronic neck pain patients, according to recent studies, 6 weeks of postural exercise training can decrease neck disability ratings, pain intensity, improve the craniovertebral angle, and neck-muscle strength.Interesting, the combination of upper thoracic spine mobilization and thoracic mobility exercise for patients will demonstrate abetter overall short-term outcome in their craniovertebral angle and cervical extension, when compared with upper cervical spine mobilization and stabilization exercise alone. However, with the combination of upper cervical and postural a stabilization exercise program we start to see a better long-term change and increased functional ability with reduces pain levels.
If you are a patient suffering from chronic neck pain or you use your smart phone with a marked cervical flexed position or you feel like your craniovertebral angle is too small, then call a skilled physical therapist. A truly talented physical therapist versed in the bio mechanical evaluation and treatment of spinal dysfunction is hard to find. Be sure that person understands the concepts of craniovertebral angle, upper crossed syndrome, postural and phasic muscles, and how to assess the gliding of your facet joints in your cervical spine and mobilize them in a safe manner for your cervical discs. That therapist should have taken additional coursework after their entry level doctorate degree and actually should be fellowship trained.