Research Review By Dr. Keshena Malik©

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Date Posted:

March 2017

Study Title:

A Comparison of the Effects of Stabilization Exercises Plus Manual Therapy to Those of Stabilization Exercises Alone in Patients with Nonspecific Mechanical Neck Pain: A Randomized Clinical Trial

Authors:

Celenay ST, Akbayrak T & Kaya DO

Author's Affiliations:

Department of Physiotherapy and Rehabilitation, Health Science Faculty, Yildirim Beyazit University, Ankara, Turkey; Department of Physiotherapy and Rehabilitation, Health Science Faculty, Hacettepe University, Ankara, Turkey; Department of Physiotherapy and Rehabilitation, Health Science Faculty, Izmir Katip Celebi University, Izmir, Turkey.

Publication Information:

Journal of Orthopaedic & Sports Physical Therapy 2016; 46(2): 44–55.

Background Information:

Manual therapy and rehabilitative exercise are both considered reasonable approaches to managing mechanical neck pain (MNP). However, there is a dearth of RCTs investigating the combination of manual therapy with stabilization exercise in the treatment of MNP. Impairment of the superficial cervical muscles (i.e. increased muscle fatigability, reduction in strength and endurance, joint position sense and ROM [1-4]) and scapular function (i.e. increased activity of axio-scapular muscles and decreased activity of the lower trapezius and serratus anterior muscles [5, 6]) have been found in neck pain patients. As mentioned, rehabilitation exercises are considered an evidence-based therapeutic approach for these patients (7, 8). Spinal stabilization exercises fit into this category and have been purported to activate the deep cervical muscles, while decreasing over-activity of superficial muscles, like the sternocleidomastoid (9, 10). However, few RCTs have investigated the efficacy of cervical and scapulothoracic stabilization exercises in the management of MNP (11). In addition to exercise in the management of neck pain, manual therapies including spinal manipulation and mobilization to the cervical and thoracic joints and soft tissues have shown positive results (12-14), however no study has specifically investigated scapular mobilization for the treatment of neck disorders.

This randomized clinical trial evaluated the short-term effects of manual therapy provided in combination with cervical and scapular stabilization exercises versus stabilization exercises alone on disability, pain, ROM and quality of life in patients with non-specific, mechanical neck pain.

Pertinent Results:

Of the 116 participants screened, 102 participants met eligibility criteria. No participants withdrew from the study. No significant or clinically important differences between the groups were found at baseline. No adverse effects reported other than soreness that resolved 24-48 hours after the treatment.

Disability (measured via NDI):
The StEx+MT group experienced slightly greater improvements in disability than the St-Ex alone group. The between-group difference was 2.2 [95% confidence interval: 0.1 - 4.3], which was statistically significant but may not be clinically significant. Point estimates of the average change score (-7.6 points; 95% CI: -9.1 - -6.1) across all patients in the St-Ex+MT group exceeded the NDI’s minimal clinically important difference (MCID) of 7 points (15).

Pain (measured via VAS):
The reductions in VAS scores in both groups exceeded the MCID (VAS MCID 0.9 - 1.1cm [16]) after 4 weeks. The point estimate of the mean change scores (2.0, 2.8, and 2.6 cm) across all patients in the StEx+MT group also exceeded the MCID (generally accepted as 0.9 - 1.1cm) on the VAS at rest, with activity, and at night (respectively) (16). The biggest difference was noted in night-time pain, with the between group difference in change scores being statistically significant, favouring the StEx+MT group (VAS = 1.1cm, p = 0.04).

Pressure Pain Threshold (PPT):
No significant between group difference was noted for PPT.

Cervical ROM:
Patients in the StEx+MT group demonstrated a greater improvement in cervical rotation motions than those in the StEx-only group (right rotation = 4.3 [95% CI: -8.1 - -0.5], p = 0.02; left rotation = -5.0 [95% CI: -8.2 - -1.7], P = 0.003). The differences in cervical flexion, extension and bilateral lateral flexion motions were small.

Quality of Life (measured via SF-36):
Patients who received St-Ex+MT showed significantly greater improvements in quality of life in both physical (-2.9, [95% CI: -5.4 - -0.4]) and mental (-3.1, [95% CI: -6.2 - 0.0]) component summaries compared to those who received St-Ex only.

Clinical Application & Conclusions:

The combination of cervical and scapulothoracic stabilization exercises and mobilizations employed in this study, implemented over a period of 4 weeks, was superior to stabilization exercises alone in the treatment of patients with non-specific mechanical neck pain in terms of disability, night pain intensity, cervical rotation ROM and quality of life. Appropriate administration of manual therapy and rehabilitative exercise is in line with current clinical practice guidelines and can be easily implemented in clinical practice to improve patient outcomes.

Study Methods:

Participants

Participants had to fulfill the following criteria to be eligible for this study:
  • Between the ages of 18-65
  • Received a diagnosis of mechanical neck pain (MNP) from their physician
  • Generalized neck pain for more than 3 months, with symptoms worsened by neck postures, movements or palpation
Participants were excluded from the study for the following reasons:
  • Inflammatory rheumatologic disease, malignancy or structural deformity causing neck pain
  • Previous cervical spine surgery, spinal stenosis or bilateral upper extremity (UE) symptoms
  • 2 or more positive radicular signs of nerve root compression (UE muscle weakness, diminished deep tendon reflex, diminished or absent sensation to pinprick in dermatome)
  • Severe referred pain (> 7 points on a Visual Analogue Scale) in the related UE dermatome
  • Capsular pattern indicative of arthritis
  • Severe psychological disorder
  • Pregnancy
  • Any intervention including exercise or physical therapy in the last 3 months
Procedures

The following demographic variables were evaluated:
  • Age
  • Gender
  • Height/weight
  • Exercise habits
  • Smoking and alcohol consumption
  • Mechanism of injury (if applicable)
  • Location and duration of symptoms
Active and passive movement testing for cervical and UE muscle weakness, vertebral basilar artery test, L’Hermitte sign, UE tension test and DTR and sensory exam were also performed.

Randomization, Sample Size and Statistics:
Patients were randomly assigned to receive a stabilization exercise program without manual therapy (StEx only) or with manual therapy (StEx+MT) using a computer-generated randomized table. The treating therapist, blinded to the baseline assessment findings, proceeded with treatment according to random group assignment. Sample size calculated to be at least 51 patients per group (assuming standard deviation of 7 NDI scale points, 2-tailed test at alpha 0.05, power 80% and 20% drop-out). Statistical analysis included:
  • Normal distribution (histogram and Shapiro-Wilk test)
  • 2-way mixed-model ANOVA to examine effects of primary and secondary outcome measures (OM)
  • Pairwise comparisons (Bonferroni correction) to examine differences from baseline to final treatment session between groups
Outcome Measures

At baseline and after 4 weeks, the following outcomes were evaluated by the same physical therapist who was blinded to the treatment group, using a standardized protocol. The primary outcome measure was the Neck Disability Index (NDI, in Turkish), while secondary outcomes included the presence of pain at rest, during activity and at night, measured using Visual Analog Scale (VAS), pressure pain threshold (PPT) measured three times bilaterally (the average PPT measurement employed in the analysis) using a digital algometer placed on the mid-point of the upper trapezius muscle, cervical ROM measured three times for each direction using a goniometer, and the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) Turkish version.

Interventions

The interventions were administered 3 times per week for 4 weeks by an experienced physical therapist. Each exercise session began with a 10 minute warm up, 40 minutes of stabilization exercises, a 10 minute cool down and stretches of the neck and shoulder girdle muscles. Sessions began with postural education in seated position in front of mirrors (front and side) and adopt a neutral spine. Before each exercise, participants were taught a cervical bracing technique (i.e. to perform a contraction of the deep neck flexors) with biofeedback correction provided by the Chatanooga Stabilizer Pressure Biofeedback Unit.

Progressive Cervical and Scapulothoracic Stabilization Exercise Program:
Once neutral spine and cervical bracing were employed, the following exercise program was completed by each participant:
  • Hold the cervical bracing contraction for 10 seconds in each position (supine, prone, quadrupedal and bipedal) with 10 repetitions
  • Extremity ROM exercises
  • Cervical isometric exercises performed using elastic resistance bands forward, backward, obliquely bilaterally and to the left and right for 10 reps with a 6-10 second hold.
  • Functional training on unstable surfaces for 10 reps, with a 10-15 second hold: sitting on an exercise ball, progressing to raise one arm forward to 90 degrees, then both arms; standing with exercise ball against wall with the ball placed behind the neck and shoulders (position A) then switching to the ball on forehead (position B); standing with exercise ball in position A, abducting both shoulders to 90 degrees holding resistance bands, then switch to position B and perform same; standing holding ball in hands raise ball above head then perform a squat
  • Once the thoracic bracing technique with postural alignment and minimal multifidus muscle activation was assumed (17), scapulothoracic stabilization exercises were completed using resistance band which performing: scapular adduction and shoulder external rotation, bilateral shoulder extension with scapular retraction, eccentric scapular retraction, Brügger exercise, forward punch and dynamic hug
All exercise repetitions increased progressively from 8-12 reps depending on patient requirement.

Mobilization Application:
Appropriate mobilization techniques were provided according to the patients’ specific requirements. The following mobilization techniques were directed to the cervical (#1-5, with treatment application time of 10-15 minutes) and scapular (#6) regions:
  1. Bridging technique –supine (head tilt at occiput into extension with added traction)
  2. Manual traction - supine
  3. Rotation during traction – supine, bilaterally,
  4. Anterior/posterior gliding during traction - supine
  5. Lateral gliding - supine
  6. Scapular mobilization – side-lying, 10 repetitions each of scapular distraction and gliding superior/inferior and rotational directions

Study Strengths / Weaknesses:

Strengths:
  • This is the first RCT investigating the short-term effects of cervical and scapulothoracic mobilization techniques in combination with stabilization exercises in the treatment of MNP, which provides a meaningful foundation upon which future studies can be built.
  • The authors appropriately described both their rehab and manual therapy interventions.
  • No participants dropped out of the study.
Weaknesses:
  • The 4 week treatment period precludes inferences on long-term outcomes and may not be generalizable.

Additional References:

  1. Barton PM & Hayes KC. Neck flexor muscle strength, efficiency, and relaxation times in normal subjects and subjects with unilateral neck pain and headache. Arch Phys Med Rehabil 1996; 77(7): 680-687.
  2. Chiu TT & Lo SK. Evaluation of cervical range of motion and isometric neck muscle strength: reliability and validity. Clin Rehabil 2002; 16(8): 851-858.
  3. Falla D & Farina D. Muscle fiber conduction velocity of the upper trapezius muscle during dynamic contraction of the upper limb in patients with chronic neck pain. Pain 2005; 116(1-2): 138-145.
  4. Ylinen J, Salo P, Nykänen M, et al. Decreased isometric neck strength in women with chronic neck pain and the repeatability of neck strength measurements. Arch Phys Med Rehabil 2004; 85: 1303-1308.
  5. Jull G, Sterling M, Falla D et al. Whiplash, Headache, and Neck Pain: Research- Based Directions for Physical Therapies. Edinburgh, UK: Elsevier/Churchill Livingstone; 2008.
  6. Zakharova-Luneva E, Jull G, Johnston V et al. Altered trapezius muscle behavior in individuals with neck pain and clinical signs of scapular dysfunction. J Manipulative Physiol Ther 2012; 35(5): 346-353.
  7. Chiu TT, Lam TH, Hedley AJ. A randomized controlled trial on the efficacy of exercise for patients with chronic neck pain. Spine 2005; 30(1): E1-E7.
  8. Kay TM, Gross A, Goldsmith CH et al. Exercises for mechanical neck disorders. Cochrane Database Syst Rev 2012; 8:CD004250.
  9. Hides JA, Jull GA, Richardson CA. Long-term effects of specific stabilizing exercises for first-episode low back pain. Spine 2001; 26(11): E243-E248.
  10. Stuge B, Laerum E, Kirkesola G et al. The efficacy of a treatment program focusing on specific stabilizing exercises for pelvic girdle pain after pregnancy: a randomized controlled trial. Spine 2004; 29(4): 351-359.
  11. Wegner S, Jull G, O’Leary S et al. The effect of a scapular postural correction strategy on trapezius activity in patients with neck pain. Man Ther 2010; 15(6): 562-566.
  12. Vincent K, Maigne JY, Fischhoff C, et al. Systematic review of manual therapies for nonspecific neck pain. Joint Bone Spine 2013; 80(5):508-515.
  13. Gross AR, Goldsmith C, Hoving JL, et al. Conservative management of mechanical neck disorders: a systematic review. J Rheumatol 2007; 34(5): 1083-1102.
  14. Izquierdo Pérez H, Alonso Perez JL, Gil Martinez A, et al. Is one better than another?: A randomized clinical trial of manual therapy for patients with chronic neck pain. Man Ther 2014; 19(3): 215-221.
  15. Abbott JH & Schmitt J. Minimum important differences for the Patient-Specific Functional Scale, 4 region-specific outcome measures, and the numeric pain rating scale. J Orthop Sports Phys Ther 2014; 44(8): 560-564.
  16. Bird SB, Dickson EW. Clinically significant changes in pain along the visual analog scale. Ann Emerg Med 2001; 38(6): 639-643.
  17. Mottram SL, Woledge RC, Morrissey D. Motion analysis study of a scapular orientation exercise and subjects’ ability to learn the exercise. Man Ther 2009; 14(1): 13-18.