It adds to the growing diversity of opinion of the hypothesised mechanisms of motor control in LBP. This is an important reminder that there should be a separation between the research question asking if the treatment works, and how or why the treatment works. Too many therapists and researchers rely on one to justify the other. “
“The Western Ontario Rotator Cuff Index (WORC) is a condition-specific self-reported instrument to assess ‘quality of life’ (QoL) (Kirkley et al 2003). It consists of 21 visual analog scale (VAS)
items organised in 5 subscales: physical symptoms, sports/recreation, work, lifestyle, and emotions. It was developed by a clinimetric PFI-2 in vivo process. The origins of the subscale structure were not established SCH900776 by a factor analysis; and are
similar to those contained on instruments developed by the same author for other shoulder conditions (osteoarthritis and instability) (Lo et al 2001). The WORC has been translated and validated in several languages. Instructions to client and scoring: Patients are asked to indicate on a 100-mm line, anchored at the beginning and at the end, the extent to which the symptom or disability is experienced over the past week referring to the problematic shoulder. Phrases like ‘no pain’ and ‘extreme pain’, ‘no weakness’ and ‘extreme weakness’, ‘no difficulty’ and ‘extreme difficulty’ which explained the extremes of a particular item measured, were used as anchors. Each item in WORC has a possible score from 0–100 (100 mm VAS). Scores can be computed for individual subscales and summated for a total score, which can range from 0–2100, with a higher score representing lower quality of life. To present this in a more clinically meaningful format, the distance from the left side of the line is measured and recorded to the nearest 0.5 mm, calculated for a score of out of 100, and summed for each subscale (physical
symptoms/600, sports and recreation/400, work/400, lifestyle/400, and emotions/400). Casein kinase 1 The subscale scores are summed and reported as a percentage of normal by subtracting the total from 2100, dividing by 2100, and multiplying by 100 (Kirkley et al 2003). Reliability, validity and responsiveness: The WORC has demonstrated good test-retest reliability across several studies (ICCs 0.84 to 0.96) (Kirkley et al 2003, Ekeberg et al 2008, de Witte et al 2012). The construct validity of WORC as determined by comparison to other disability instruments has been supported (Longo et al 2011). The WORC correlates with the American Shoulder and Elbow Surgeons score (ASES) (r = 0.68) and the Disabilities of the arm, shoulder and hand (DASH) (r = 0.63) (Kirkley et al 2003). Factor validity of the 5-domain structure of WORC has been questioned. In one study 3 factors (symptoms and emotional items, strength items, daily activities) were identified representing 57% of variance (Wessel et al 2005).