Research Review by Dr. Shawn Thistle©

Date:

Aug. 2007

Study Title:

Effect of neck exercise on sitting posture in patients with chronic neck pain

Authors:

Falla D et al.

Publication Information:

Physical Therapy 2007; 87: 408-417.

Summary:

Manual therapists in many disciplines have always espoused that proper posture promotes good general health. Anecdotally, it believed that poor sitting posture can initiate, or perpetuate, mechanical neck pain and some headache syndromes. Most experienced practitioners will agree that patients with chronic neck pain report aggravation of their pain when they adopt forward head posture for long periods when sitting, computing, or driving.

The craniocervical region is supported locally by deep muscles that attach to the cranium and span the upper cervical segments, such as the longus capitus, longus colli, and suboccipital muscles. Support is also provided by global muscles which also attach to the cranium, but extend to the thoracic cage and shoulder girdle, such as the semispinalis cervicis, splenius capitus, and levator scapulae. All of these muscles are commonly assessed and treated by manual therapists of all disciplines when dealing with neck pain and headaches.

Recent studies have suggested that dysfunction of the deep cervical neck flexors can correlate with neck pain and headaches. Different methods of retraining these muscles have been proposed, with the goal of increasing activation and endurance of these muscles.

This study had two purposes:
  1. to assess postural changes in neck pain patients during a distracting computer task
  2. to compare the effects of 2 different neck exercise programs on the ability of neck pain patients to maintain upright posture during the same task
Fifty-eight female subjects (average age ~38) with a history of chronic, non-severe neck pain for longer than three months participated in this study. Ten volunteers without neck pain formed the control group. Subjects had to score no more than 15 on the Neck Disability Index, as scores greater than 15 indicate moderate neck pain.

Further, subjects had to have palpable joint tenderness and demonstrate poor performance on a clinical test for craniocervical flexion as described by Jull et al. Exclusion criteria included having participated in a neck exercise program in the previous 12 months, neurological findings on examination, and previous cervical spine surgery.

In Phase 1 of the study, subjects were positioned in front of a computer with their knees at 90° of flexion and their feet flat on the floor. Postural analysis (see technique below) was performed while subjects were playing a game of Solitaire on the computer for 10 minutes.

Postural Analysis Technique

All patients were seated in a standard manner, with a plumb line in the background serving as a reference. Throughout the 10 minute task, digital photos were taken from a standard position and distance from the subject. Cervical-thoracic posture angles were measured using the plumb line and a line joining anatomical markers on the tragus and spinous process of C7.

In Phase 2 of the study, subjects with chronic neck pain were randomized into one of two exercise groups:
  1. Craniocervical Muscle Training Regimen following the protocol described by Jull et al. – using an air-filled pressure sensor behind the neck, patients were verbally guided to “gently nod your head” into craniocervical flexion at 5 predetermined pressure targets in 2mm-Hg increments, which were held for 10 seconds – once a specific level could be held for 10 repetitions, subjects were progressed to the next level.
  2. Endurance-Strength Training Regimen for the cervical flexor muscles. This progressive resistance program for the neck flexors was performed with patients in a supine position. They were instructed to lift their head while maintaining neutral upper cervical position. This program was performed in 2 stages: 1) 2 weeks of 12-15 repetitions with a weight that could initially be lifted 12 times and 2) 4 weeks performing 3 sets of 15 reps with weight added as needed in 0.5 Kg increments.
Each program was performed over a 6 week period. Subjects received personal instruction and supervision once per week in both groups. No individual exercise session lasted longer than 30 minutes. Subjects were asked not to receive any additional treatment for their neck pain, and were to perform their exercise program at home for 10-20 minutes per day.

Upon completion of the exercise programs, the initial distraction task with postural analysis was repeated.

Pertinent Results:

  • neck pain subjects demonstrated a significant, progressive increase in cervical and thoracic angle throughout the 10 minute task, while control subjects only showed only a small change in thoracic angle
  • all subjects received all 6 exercise sessions, and according to exercise diaries, patient adherence to home exercise was > 90% in both groups
  • both exercise groups demonstrated a reduction in average pain intensity after the 6 week training period
  • after training, both groups were able to better maintain thoracic posture, while only the Craniocervical Muscle Training group had a significant improvement in cervical posture

Conclusions & Practical Application:

This small study demonstrated that patients with non-severe chronic neck pain had a reduced ability to maintain an upright, neutral posture during a computer task, and that this deficit could be reduced after a training program aimed at the deep cervical flexor musculature. This type of training as well as the strength-endurance program also seemed to have a positive effect on pain levels.

Evidence is mounting that simple, low tech rehabilitation techniques can have a positive impact on mechanical neck pain and posture. As a component of a holistic treatment program, manual therapists can easily implement this type of exercise either in-office, or as a home program.