Abstract
Background: Shoulder pain is the third leading cause of musculoskeletal complaints presenting in primary care. Rotator cuff-related shoulder pain is an umbrella diagnostic label used to encompass disorders associated with rotator cuff problems and is the most common diagnosis of shoulder pain. Joint mobilisation is widely used to treat patients with rotator cuff-related shoulder pain. However, the evidence supporting joint mobilisation for improving shoulder range of motion (ROM) and pain intensity in patients with rotator cuff-related shoulder pain is limited. This thesis aimed to: (1) summarise the type and dosage of joint mobilisations and the rationale for selecting a specific dosage of joint mobilisation for patients with rotator cuff-related shoulder pain; (2) assess the reliability of movement-evoked pain in patients with rotator cuff-related shoulder pain; (3) assess the reliability of quantitative sensory testing in patients with rotator cuff-related shoulder pain; (4) explore the associations of movement-evoked pain with pain intensity at rest, shoulder pain and disability, psychological factors, or quantitative sensory testing in patients with rotator cuff-related shoulder pain; and (5) explore the initial effect of mobilisation with movement (MWM) on shoulder ROM and pain intensity in patients with rotator cuff-related shoulder pain and whether the dosage of MWM influences the effect of MWM in patients with rotator cuff-related shoulder pain.
Methods: This thesis includes five studies. Chapter 3 (scoping review) summarised the reported type and dosage of joint mobilisation and the rationale for adopting a specific dosage for patients with rotator cuff-related shoulder pain from previous studies. Randomised controlled trials using joint mobilisation for patients with rotator cuff-related shoulder pain were included in the scoping review if they reported at least some information on types or dosages of joint mobilisation. Chapters 5 and 6 assessed the test-retest reliability of movement-evoked pain and quantitative sensory testing in patients with rotator cuff-related shoulder pain, respectively. Chapter 7 explored the associations of movement-evoked pain with pain intensity at rest, shoulder pain and disability, psychological factors, or quantitative sensory testing in patients with rotator cuff-related shoulder pain. Chapter 8 explored the initial effects of MWM on shoulder ROM and pain intensity in patients with rotator cuff-related shoulder pain and whether the dosage of MWM influences clinical outcomes in patients with rotator cuff-related shoulder pain using a randomised controlled trial. Participants with rotator cuff-related shoulder pain were recruited at the same time for Chapters 5-8. Chapters 5-7 used data from the same sample under the same experimental condition before participants received any interventions in Chapter 8. Of those participants in Chapters 5-7, participants were recruited for Chapter 8 if they were positively responded to MWM. The test-retest reliability of movement-evoked pain and quantitative sensory testing in Chapter 5 and Chapter 6 was examined using the intra-class correlation coefficient (ICC3, 1) and the minimal detectable change (MDC95%). The associations of movement-evoked pain with pain intensity at rest, shoulder pain and function, psychological factors, or quantitative sensory testing outcome measures were analysed using Pearson correlation coefficient in Chapter 7. In Chapter 8, the primary outcome angular onset of pain was measured at baseline, after receiving the first and third sets of 10 repetitions of MWM or sham MWM intervention. A linear mixed-effects model with a random intercept was used to compare the changes in angular onset of pain (from baseline to the time after receiving the first set and third set of interventions, respectively) between the MWM and sham MWM groups.
Results: Thirty-two randomised controlled trials were included in scoping review. The scoping review found that most included studies reported little information about the dosage of passive joint mobilisation implemented in previous studies, with a heterogeneous dosage being tested across different studies. Most studies assessing the effect of MWM implemented within-session dosage of 3 sets of 10 repetitions. The rationale for selecting the dosage of joint mobilisation was very limited and had, most of the time, no scientific evidence to support it. Seventy-four participants with rotator cuff-related shoulder pain were recruited for Chapters 5-7. Sixty-three participants with rotator cuff-related shoulder pain participated in Chapter 8. Chapters 5 and 6 demonstrated that the reliability of movement-evoked pain and quantitative sensory testing measures ranged from good to excellent (ICC ≥ 0.77) in patients with rotator cuff-related shoulder pain. Findings from Chapter 7 suggest that the pain intensity, rather than ROM, of movement-evoked pain shares similar constructs with pain intensity at rest, shoulder pain and disability and psychological factors in patients with rotator cuff-related shoulder pain during shoulder abduction to the onset of pain or shoulder abduction to the maximum range. Findings from Chapter 8 suggested no differences between MWM and sham MWM groups in the angular onset of pain after receiving 1 set of 10 repetitions (mean difference 6.5°, 95% CI -0.9 to 13.9). However, findings showed the MWM group had an extra improvement in the angular onset of pain of 13.7° (95% CI 6.3 to 21.1) after receiving 3 sets of 10 repetitions of interventions when compared with the sham MWM group.
Conclusion: This thesis highlighted little is known about the dosages tested within previous studies assessing the effect of joint mobilisation techniques on clinical outcomes. These findings highlight the importance of detailed reporting for the dosage of joint mobilisation and the need for a clear rationale to support its use. This thesis confirmed that movement-evoked pain and quantitative sensory testing are reliable testing procedures for assessing patients with rotator cuff-related shoulder pain. Pain intensity of movement-evoked pain shares similar constructs with pain intensity at rest, shoulder pain and disability, and psychological factors in patients with rotator cuff-related shoulder pain. This thesis also confirmed that MWM improves the angular onset of pain after 3 sets of 10 repetitions of MWM in patients with rotator cuff-related shoulder pain. The findings of this thesis provide preliminary support for the use of MWM in treating patients with rotator cuff-related shoulder pain and provide some guidance for clinicians to decide the MWM dosage to be used in clinical practice.