Can a physical activity monitor provide a valid measure of arm elevation angle? A study to assess agreement between the SenseWear Mini Armband and the universal goniometer.

BACKGROUND: We undertook the current study to assess whether an accelerometer-based physical activity monitor, the SenseWear Mini Armband (SMA), could be used to provide data on static arm elevation, and to assess the agreement between static arm elevation measures obtained using SMA-derived data and those obtained with a universal goniometer. METHODS: Using a universal goniometer, healthy adult subjects (n = 25, age 30 ± 9 years) had each of right and left arms positioned in a series of set positions between arm-by-side and maximal active arm flexion (anteversion), and arm-by-side and maximal active arm abduction. Subjects wore the SMA throughout positioning, and SMA accelerometer data was used to retrospectively calculate/derive arm elevation angle using a manufacturer-provided algorithm. The Bland-Altman method was used to assess agreement between goniometer-set and SMA-derived arm elevation angles. RESULTS: There were significant differences between goniometer-set and SMA-derived arm elevation angles for elevation angles ≤ 30 degrees and ≥ 90 degrees (p < 0.05). Bland-Altman plots showed that the greater the angle of elevation, the greater the mean difference between goniometer-set and SMA-derived elevation angles. Adjustment of the manufacturer-provided algorithm for deriving arm elevation angle corrected for this systematic difference, and resulted in 95% limits of agreement ± 12 degrees (flexion) and ± 13 degrees (abduction) across the full range of arm elevation. CONCLUSIONS: The SMA can be used to record data allowing derivation of static arm elevation angle in the upright position, 95% limits of agreement with the universal goniometer being similar to those reported for digital inclinometers and gyroscopes. Physiotherapists looking for innovative methods of recording upper limb range of motion should consider the potential of accelerometer-based physical activity monitors such as the SMA.

Motor Imagery Performance and Tactile Spatial Acuity: Are They Altered in People with Frozen Shoulder?

Frozen shoulder (adhesive capsulitis) is a severe chronic pain condition that is not well understood and current treatment is suboptimal. In several other chronic pain conditions motor imagery and tactile acuity deficits are present, which are thought to represent associated neuroplastic changes. The aims of this study were to determine if motor imagery performance assessed by the left/right judgement task, and tactile acuity assessed by two-point discrimination, are altered in people with unilateral frozen shoulder. In this cross-sectional, prospective study eighteen adults diagnosed with frozen shoulder in a physiotherapy clinic setting completed a left/right judgement task, response times (RT) and accuracy for the left/right judgement task were determined. Next, tactile acuity over both shoulders was assessed with a novel, force-standardised two-point discrimination test. Results corresponding to the affected side were compared to the pain free shoulder; Left/right judgement task: mean RT (SD) corresponding to the affected shoulder was significantly slower than RT for the healthy shoulder (p = 0.031). There was no side-to-side difference in accuracy (p > 0.05). Neither RT nor accuracy was related to pain/disability scores or duration of symptoms (p > 0.05). Two-point discrimination: mean two-point discrimination threshold of the affected shoulder was significantly larger than the contralateral healthy shoulder (p < 0.001). Two-point discrimination threshold was not related to pain/disability scores or pain duration (p > 0.05); One explanation for these findings is altered sensorimotor processing and/or disrupted sensorimotor cortex representations of the affected shoulder. A case then exists for the use of treatments aimed at reversing these changes, training the brain to reduce chronic shoulder pain.

Is implicit motor imagery altered in people with shoulder pain? The shoulder left/right judgement task.

BACKGROUND: Implicit motor imagery performance is altered in a variety of chronic pain conditions, but it is not known whether this is the case in shoulder pain. OBJECTIVES: The aim of this study was to assess implicit motor imagery performance, using a valid and reliable shoulder left/right judgement task in people with shoulder pain. DESIGN: Cross-sectional observational study. METHODS: Participants with (n = 369) and without (n = 747) shoulder pain completed the shoulder left/right judgement task (LRJT). Response times (RT), accuracy were determined. Age, gender, hand dominance, current pain intensity, Shoulder Pain and Disability Index (SPADI) and pain duration recorded. Planned analysis included ANOVAs for current pain, RT and accuracy. RESULTS: Gender and hand dominance distribution were similar between groups (p > 0.5). The shoulder pain participants were older, mean age (SD); 47(14)years, than the control group; 41(14)years, p < 0.01. Participants with shoulder pain were slower, mean RT(SD); 1809(746)ms than the controls; 1701(749)ms; p = 0.02, but no different in accuracy, mean % (SD); 93.2(8.5)% to controls; 94.1(9.4)%; p = 0.13. The differences in RT were resolved when age was entered as a covariate (p = 0.83). Regression of the data from the shoulder pain group only found that current pain was positively related to RT (B = 43.97) and negatively to accuracy (B = -0.70). CONCLUSIONS: Participants with shoulder pain do not demonstrate poorer implicit motor imagery performance than people who are pain-free. However, more intense shoulder pain is associated with poorer implicit motor imagery performance. We recommend further research utilising the LRJT in well-defined clinically homogenous groups, with verified pain severity, functional disability, and chronicity.

Do People With Chronic Musculoskeletal Pain Have Impaired Motor Imagery? A Meta-analytical Systematic Review of the Left/Right Judgment Task.

The left/right judgment task (LRJT) is the most commonly used method of assessing motor imagery performance. Abnormally long response times are thought to reflect delayed processing of body/spatial representations, and poor accuracy is thought to reflect disrupted cortical proprioceptive representations or body schema. Slower and less accurate responses on the LRJT have been reported in a variety of chronic musculoskeletal pain conditions. To date, no systematic review of the literature has been conducted to assess if altered motor imagery performance as measured by the LRJT is characteristic of all chronic musculoskeletal pain conditions. Therefore, the aim of this study was to conduct a comprehensive systematic review and meta-analysis of the literature to answer the following question: Do people with chronic musculoskeletal pain have impaired left/right body part judgment? Twenty-five studies (2,266 participants) including a range of chronic pain populations who undertook an LRJT were identified from searches of 8 electronic databases from inception to March 2017. Results indicate that chronic musculoskeletal pain conditions affecting the limbs and face (P ≤ .01) are associated with altered motor imagery performance as measured by the LRJT. PERSPECTIVES: This review synthesizes evidence of altered motor imagery performance using the LRJT across chronic musculoskeletal pain conditions. Consistent evidence was found for altered motor imagery performance in peripheral pain conditions, but evidence was less consistent for axial conditions. Treatment to restore a normal body schema may be beneficial in chronic limb and facial pain.

The development of a shoulder specific left/right judgement task: Validity & reliability.

BACKGROUND: Disruption of cortically-held working body schema has been associated with a variety of pain conditions. A motor imagery technique - the left right judgement task (LRJT) - has been used as an indirect assessment of the integrity of the working body schema. To date there is no LRJT specifically designed to investigate the body schema of persons with shoulder pain. OBJECTIVES: To develop a shoulder specific LRJT and assess its validity and reliability. DESIGN: Cross-sectional repeated measures. METHODS: Shoulder images were developed representing the shoulder in a variety of postures of graded complexity/awkwardness and degree of rotation. These images were digitally mirrored to represent both left and right shoulders. Participants viewed the images on a computer and determined whether images were of a left or right shoulder. RESULTS: 1413 participants were recruited worldwide and performed the shoulder LRJT (laterality judgement). Mean response time (SD) for the task was 1738(741) ms. Mean accuracy (SD) was 93.5(9.2)%. Chronbach's Alpha for shoulder image response times was 0.95. Participants were fastest responding to images of simple postures and slowest to images corresponding to the more awkward postures (mean difference 520 ms, 95%CI 469-570 ms). Participants were fastest responding to the least rotated images and slowest responding to inverted images, (mean difference 981 ms, 95%CI 919-1043 ms). CONCLUSIONS: The shoulder specific LRJT proved to be highly reliable. Response times increased with complexity and rotation of images, implying a motor imagery strategy was used to complete the task, validating the task as a measure of shoulder joint implicit motor imagery. Abnormal performance cut-offs for age were reported. This result will enable further research examining the relationship between shoulder pain and body schema.

Shoulder Pain and Disability Index (SPADI).

The Shoulder Pain and Disability Index (SPADI) was developed to measure current shoulder pain and disability in an outpatient setting. The SPADI contains 13 items that assess two domains; a 5-item subscale that measures pain and an 8-item subscale that measures disability. There are two versions of the SPADI; the original version has each item scored on a visual analogue scale (VAS) and a second version has items scored on a numerical rating scale (NRS). The latter version was developed to make the tool easier to administer and score (Williams et al 1995). Both versions take less than five minutes to complete (Beaton et al 1996, Williams et al 1995). The questionnaire was developed and initially tested in a mixed diagnosis group of male patients presenting to ambulatory care reporting shoulder pain (Roach et al 1991). The SPADI has since been used in both primary care on mixed diagnosis (Beaton et al 1996, MacDermaid et al 2006) and surgical patient populations including rotator cuff disease (Ekeberg et al 2008), osteoarthritis, and rheumatoid arthritis (Christie et al 2010), adhesive capsulitis (Staples et al 2010, Tveita et al 2008), joint replacement surgery (Angst et al 2007), and in a large population-based study of shoulder symptoms (Hill et al 2011). The SPADI is available free of charge at several sites, eg, www.workcover.com/public/download.aspx?id=799. INSTRUCTIONS TO THE CLIENT AND SCORING: In the original version the patient was instructed to place a mark on the VAS for each item that best represented their experience of their shoulder problem over the last week (Roach et al 1991). Each subscale is summed and transformed to a score out of 100. A mean is taken of the two subscales to give a total score out of 100, higher score indicating greater impairment or disability. In the NRS version (Williams et al 1995) the VAS is replaced by a 0-10 scale and the patient is asked to circle the number that best describes the pain or disability. The total score is derived in exactly the same manner as the VAS version. In each subscale patients may mark one item only as not applicable and the item is omitted from the total score. If a patient marks more than two items as non applicable, no score is calculated (Roach et al 1991). RELIABILITY AND VALIDITY: Reproducibility of the SPADI in the original description was poor, with an intraclass correlation coefficient (ICC) of 0.66. A more recent systematic review has found reliability coefficients of ICC ≥ 0.89 in a variety of patient populations (Roy et al 2009). Internal consistency is high with Cronbach α typically exceeding 0.90 (Roy et al 2009, Hill et al 2011). The SPADI demonstrates good construct validity, correlating well with other region-specific shoulder questionnaires (Paul et al 2004, Bot et al 2004, Roy et al 2009). It has been shown to be responsive to change over time, in a variety of patient populations and is able to discriminate adequately between patients with improving and deteriorating conditions (Beaton et al 1996, Williams et al 1995, Roy et al 2009). No large floor or ceiling effects for the SPADI have been observed (Bot et al 2004, Roy et al 2009). The minimal clinically important difference has been reported to be 8 points; this represents the smallest detectable change that is important to the patient (Paul et al 2004). When the SPADI is used more than once on the same subject, eg, at initial consultation and then at discharge, the minimal detectible change (MDC 95%) is 18 points (Angst et al 2008, Schmitt et al 2004). Thus some caution is advised with regard to repeated use of the instrument on the same patient. A change score of less than this value could be attributed to measurement error.