Reliability of changes in neck pain and cervical rotation range following manual scapular repositioning.

BACKGROUND: Manual scapular repositioning may result in change in neck pain and cervical rotation range. However, the reliability of such changes performed by examiners remains unknown. OBJECTIVE: To evaluate the reliability of changes in neck pain and cervical rotation range following manual scapular repositioning performed by two examiners and the agreement between these measures and patients' perceptions of change. DESIGN: Cross-sectional study. METHODS: Sixty-nine participants with neck pain and altered scapular position were recruited. Two physiotherapists performed the manual scapular repositioning. Neck pain intensity was measured using a 0-10 numerical scale and cervical rotation range with a cervical range of motion (CROM) device at baseline and in the modified scapular position. Participants' perceptions of any change were rated on a five-item Likert scale. Clinically relevant changes in pain (>2/10) and range (≥7°) were defined as "improved" or "no change" for each measure. RESULTS: ICCs for changes in pain and range between examiners were 0.92 and 0.91. For clinically relevant changes, percent agreement and kappa values between examiners were 82.6%, 0.64 for pain and 84.1%, 0.64 for range. Percent agreement and kappa values between participants' perceptions and measured changes were 76.1%, 0.51 for pain and 77.5%, 0.52 for range. CONCLUSION: Changes in neck pain and rotation range following manual scapular repositioning demonstrated good reliability between examiners. There was moderate agreement between the measured changes and patients' perceptions.

Axioscapular and neck extensor muscle behavior during isometric shoulder exertions in patients with nonspecific neck pain with and without a scapular downward rotation posture.

BACKGROUND: A common observation in persons with neck pain is scapular downward rotation (SDR) with altered muscle behavior. Evidence of changes in axioscapular muscles in neck pain patients remains inconclusive, which may reflect population heterogeneity in previous studies. RESEARCH QUESTION: Are there differences in behavior of the axioscapular (upper trapezius: UT, lower trapezius: LT and serratus anterior: SA) and neck extensor (NE) muscles during isometric shoulder tasks in patients with neck pain with SDR, patients with no scapular dysfunction and healthy controls? METHODS: Sixty participants with nonspecific neck pain (30 with SDR and 30 without scapular dysfunction) and 30 controls were recruited. Electromyographic signals were recorded unilaterally from the UT, LT, SA and NE during different isometric shoulder tasks (30° flexion, 30°abduction and 30°external rotation) at 20%, 50% and 100% maximal voluntary contraction (MVC). Activity of UT, LT, SA and NE was normalized with respect to reference contractions. The UT/LT, UT/SA and LT/SA ratios were calculated for each task. RESULTS: The neck pain group with SDR had increased UT activity in 30°flexion (20%MVC) and 30°abduction (20% and 50%MVC) compared to the neck pain and control groups without scapular dysfunction (p < 0.05). There were no between group differences in LT and SA activity (p > 0.05). The neck pain groups had greater NE activity in all tasks (p < 0.001). Finally, the neck pain group with SDR had higher UT/LT and UT/SA ratios in a few tasks at low force levels (p ≤ 0.01). SIGNIFICANCE: Greater UT activity and UT/LT and UT/SA ratios during particularly low force isometric shoulder tasks suggest that SDR is associated with altered axioscapular motor control. Greater NE activity in both neck pain groups suggests altered motor control related to neck pain. Changes in the NE and UT behavior should be considered in management of patients with neck pain with observable SDR.

Live and video observations of scapular dyskinesis in individuals with nonspecific neck pain: A reliability study.

BACKGROUND: Scapular dyskinesis (SD) has been demonstrated in neck pain patients, however reliability of SD test in this population is still lacking. OBJECTIVE: To investigate inter-rater and intra-rater (live versus video) reliability of SD by observation in neck pain patients. METHODS: Sixty-nine participants with nonspecific neck pain (31.7 ± 14.3 years) were recruited. SD was tested on the ipsilateral side of neck pain during unilateral and bilateral arm elevation. Two examiners categorized SD using two classification systems: simple (yes/no) and specific type (winging, dysrhythmia, mixed abnormality or normal). Video recordings were reviewed by one examiner. RESULTS: For inter-rater reliability, agreement and kappa (κ) values for unilateral test were 94.20%, 0.82 by simple classification and 72.46%, 0.59 by specific type. Agreement and κ values for bilateral test were 91.30%, 0.68 by simple classification and 65.22%, 0.52 by specific type. For intra-rater reliability, agreement and κ values for unilateral test were 92.75%, 0.77 by simple classification and 71.01%, 0.57 by specific type. Agreement and κ values for bilateral test were 91.30%, 0.65 by simple classification and 65.22%, 0.52 by specific type. CONCLUSION: Observation assessment demonstrated good-to-very good inter-rater and moderate-to-good intra-rater (live versus video) reliability for assessing SD in neck pain patients.

3D measurement of clavicular and scapular orientations: The association with clinical characteristics and responsiveness to scapular repositioning in patients with neck pain.

BACKGROUND: Clavicular and scapular orientations vary between neck pain patients as do clinical features and responses (changes in pain and rotation range) to scapular repositioning. Associations between these factors are unknown. OBJECTIVES: To identify subgroups of neck pain patients based on three-dimensional (3D) measures of clavicular and scapular orientations and differences between subgroups in clinical characteristics and responses to scapular repositioning. DESIGN: Cross-sectional study. METHODS: Eligible participants were recruited as part of a larger study. The 3D clavicular and scapular orientations were analyzed on the more painful side of the neck using a hierarchical cluster analysis. Clinical characteristics were neck pain location, intensity, duration, disability and presence of headache. Responses to scapular repositioning were classified as "yes and no". RESULTS: Fifty-eight participants (29 responsive; 29 non-responsive to scapular repositioning) participated in the study. Analysis identified two distinct subgroups: subgroup1 had greater clavicular retraction and scapular downward rotation (n = 26) and subgroup2 had greater clavicular elevation and scapular internal rotation and anterior tilt (n = 32). Headache and dominant pain in the upper neck were more frequent in subgroup 1 while dominant pain in the lower neck was frequent in subgroup 2 (p < 0.01). Most participants who responded positively to scapular repositioning (88.5%) were in subgroup1 and most non-responsive participants (81.2%) in subgroup2. CONCLUSIONS: The 3D clavicular and scapular orientations identified two subgroups of neck pain patients. Participants with predominantly downward scapular rotation were distinguished by pain in the upper neck, presence of headache and a positive response to scapular repositioning.

Clavicular and scapular, but not spinal kinematics vary with scapular dyskinesis type during arm elevation and lowering in persons with neck pain.

BACKGROUND: Scapular dyskinesis is often observed in patients with neck pain. However, it is unknown whether clavicular, scapular and spinal kinematics vary with different types of scapular dyskinesis during arm movement. RESEARCH QUESTION: Are there differences in clavicular, scapular and spinal kinematics during unilateral arm elevation and lowering among neck pain patients presenting with (i) scapular winging, (ii) with dysrhythmia, (iii) with no scapular abnormality and (iv) healthy controls? METHODS: Sixty participants with neck pain (20 in each group) and 20 asymptomatic controls were recruited. The 3D kinematic data were measured during unilateral arm elevation and lowering at 30°, 60°, 90°, and 120° in the scapular plane. A three-way mixed-effects ANOVA was used to determine the main effects (group, phase and angle) and the interactions between three independent variables on the kinematic data. RESULTS: The neck pain group with scapular winging had decreased clavicular retraction and increased scapular internal rotation and anterior tilt compared to the other neck pain and control groups at all angles during both phases of arm movement (p < 0.01). The neck pain group with scapular dysrhythmia had decreased scapular upward rotation compared to all other groups (p < 0.01). Some alterations in the kinematics existed during the lowering phase compared to the raising phase for all groups (p < 0.05). Spinal kinematics were similar across all groups (p > 0.05). SIGNIFICANCE: Specific patterns of clavicular and scapular kinematics were identified during arm movement relevant to the type of observed scapular dyskinesis in patients with neck pain. Such findings stand to inform more precise and relevant motor training in rehabilitation and improve understanding of the association between altered scapular kinematics and neck pain.

Neck muscle vibration produces diverse responses in balance and gait speed between individuals with and without neck pain.

BACKGROUND: Neck muscle vibration can influence cervical proprioception and sensorimotor function. It is hypothesized to affect motor performance differently in persons with and without neck pain. STUDY DESIGN: Cross-sectional study. OBJECTIVE: To clarify the extent to which vibration-induced motor responses of neck muscles affect static standing balance and gait speed in persons with and without neck pain. METHODS: Thirty participants with chronic neck pain and 30 healthy controls were recruited. Balance and gait were measured before and after 30 s of suboccipital neck muscle vibration. Balance was measured in a confortable stance with eyes closed using a swaymeter and gait using the timed 10 m walk test. RESULTS: At baseline, neck pain participants had greater postural sway, particularly in the anterior-posterior direction and slower gait speed than healthy controls (p < 0.001). Immediately after vibration, neck pain participants displayed decreased postural sway, and increased gait speed (p < 0.001). Healthy controls had increased postural sway and decreased gait speed (p < 0.001). CONCLUSION: Neck muscle vibration improved standing balance and gait speed in participants with neck pain but reduced performance in healthy controls. The study supports the importance of cervical proprioceptive information in postural control. Use of vibration could be considered neck pain patients' rehabilitation.

Effects of gender and hand dominance on size of the lower trapezius muscle.

INTRODUCTION: The influence of gender and hand dominance on the size of the lower trapezius muscle has not been studied. We aimed to identify the effects of gender and hand dominance on thickness of this muscle. METHODS: Thirty healthy subjects (15 men and 15 women) were recruited for the study. The thickness of the lower trapezius muscles was measured bilaterally at the level of T8 at rest and with contraction at 130° of shoulder abduction using ultrasound imaging. RESULTS: Men had significantly greater thickness of the lower trapezius muscle than women, both at rest and with contraction (P < 0.01). Greater lower trapezius muscle thickness was found on the dominant side compared with the non-dominant side (P < 0.05). CONCLUSION: Gender and side dominance differences should be controlled for when investigating lower trapezius muscle thickness.