Spinal manipulation is not the best therapy for non-specific chronic neck pain: a randomized controlled trial

Non-specific chronic neck pain is a common condition. There is hardly a so-called alternative medicine (SCAM) that is not advocated for it. Amongst the most common approaches are manual therapy and therapeutic exercise. But which is more effective?

This study was aimed at answering the question by comparing the effects of manual therapy and therapeutic exercise. The short-term and mid-term effects produced by the two therapies on subjects with non-specific chronic neck pain were studied. The sample was randomized into three groups:

1. spinal manipulation (n=22),
2. therapeutic exercise (n=23),
3. sham treatment (n=20).

The therapists were physiotherapists. Patients were not allowed any other treatments that the ones they were allocated to. Pain quantified by visual analogue scale, the pressure pain threshold, and cervical disability quantified by the Neck Disability Index (NDI) were the outcome measures. They were registered on week 1, week 4, and week 12.

No statistically significant differences were obtained between the experimental groups. Spinal manipulation improved perceived pain quicker than therapeutic exercise. Therapeutic exercise reduced cervical disability quicker than spinal manipulation. Effect size showed medium and large effects for both experimental treatments.

The authors concluded that there are no differences between groups in short and medium terms. Manual therapy achieves a faster reduction in pain perception than therapeutic exercise. Therapeutic exercise reduces disability faster than manual therapy. Clinical improvement could potentially be influenced by central processes.

The paper is poorly written (why do editors accept this?) but it laudably includes detailed descriptions of the three different interventions:

Group 1: Manual therapy

“Manual therapy” protocol was composed of three techniques based on scientific evidence for the treatment of neck pain. This protocol was applied in the three treatment sessions, one per week.

1. 1. 1.High thoracic manipulation on T4. Patients are positioned supine with their arms crossed in a “V” shape over the chest. The therapist makes contact with the fist at the level of the spinous process of T4 and blocks the patient’s elbows with his chest. Following this, he introduces flexion of the cervical spine until a slight tension is felt in the tissues at the point of contact. Downward and cranial manipulation is applied. If cavitation is not achieved on the first attempt, the therapist repositions the patient and performs a second manipulation. A maximum of two attempts will be allowed in each patient.
   2. 2.Cervical articular mobilization (2 Hz, 2 min × 3 series). The patient is placed on the stretcher in a prone position, placing both hands under his forehead. The therapist makes contact with his two thumbs on the spinous process of the patient’s C2 vertebra and performs grade III posteroanterior impulses at a speed of 2 Hz and for 2 min. There are 3 mobilization intervals with a minute of rest between each one of them [13].
   3. 3.Suboccipital muscle inhibition (3 min). With the patient lying supine, the therapist places both hands under the subject’s head, by contacting their fingers on the lower edge of the occipital bone, and exerts constant and painless pressure in the anterior and cranial direction for 3 min.

Group 2: Therapeutic exercise

“Therapeutic exercise” protocol: this protocol is based on a progression in load composed of different phases: at first, activation and recruitment of deep cervical flexors; secondly, isometric exercise deep and superficial flexors co-contraction, and finally, eccentric recruitment of flexors and extensors. This protocol, as far as we know, has not been studied, but activation of this musculature during similar tasks to those of our protocol has been observed. This protocol was taught to patients in the first session and was performed once a day during the 3 weeks of treatment, 21 sessions in total. It was reinforced by the physiotherapist in each of the three individual sessions.

Week 1: Exercises 1 and 2.

1. 1. 1.Cranio-cervical flexion (CCF) in a supine position with a towel in the posterior area of the neck (3 sets, 10 repetitions, 10 s of contraction each repetition with 10 s of rest).
   2. 2.CCF sitting (3 sets, 10 repetitions, 10 s of contraction each repetition with 10 s of rest)

Week 2: Exercises 1, 2, 3, and 4.

1. 1. 3.Co-contraction of deep and superficial neck flexors in supine decubitus (10 repetitions, 10 s of contraction with 10 s of rest).
   2. 4.Co-contraction of flexors, rotators, and lateral flexors. The patients performed cranio-cervical flexion, while the physiotherapist asked him/her to tilt, rotate, and look towards the same side while he/she opposes a resistance with his/her hand (10 repetitions, 10 s of contraction with 10 s of rest).

Week 3: Exercises 1, 2, 3, 4, 5, and 6.

1. 1. 5.Eccentric for extensors. With the patient seated, he/she should perform cervical extension. Then, he/she must realize a CCF and finish doing a cervical flexion (10 repetitions).
   2. 6.Eccentric for flexors. The patients, placed in a quadrupedal and neutral neck position, should perform neck flexion; then, they must have done a cranio-cervical flexion and, maintaining that posture, extend the neck and then finally lose the CCF (10 repetitions).

Group 3: Sham treatment

For the “control” protocol, the patients were placed in the supine position, while the physiotherapist placed his hands without therapeutic intention on the patient’s neck for 3 min. The physiotherapist simulated the technique of suboccipital inhibition. Later, with the laser pointer off, patients were contacted without exerting pressure for 10 s. Patients assigned to the control group received treatment 1 or 2 after completing the study.

This study has many strengths and several weaknesses (for instance the small sample sizes). Its results are not surprising. They confirm what I have been pointing out repeatedly, namely that, because exercise is cheaper and has less potential for harm, it is by far a better treatment for chronic neck pain than spinal manipulation.