Background 3-D movement analysis with electromagnetic tracking systems proved to be a reliable tool in measuring range of motion (ROM) in healthy shoulders. 3-D analysis of movement patterns in subjects with pain and movement limitations of the shoulder has not yet been performed.
Objectives To investigate 3-D movement patterns of the affected and non-affected shoulder in patients with a frozen shoulder before and after physical therapy.
Methods Patients with a unilateral frozen shoulder were assessed before and after 3 months of intensive passive end-range of motion mobilisation techniques. 3-D movement analysis was performed with the ?Flock of Birds®? electromagnetic tracking device while the patient elevated the arms in 3 directions. Using segmented linear regression, the characteristic slope of the upward part of the curves of glenohumeral elevation angle (x-axis) versus scapular laterorotation angle (y-axis) was approximated. Within this analysis determining the turning point of the curve was essential. Additional measures included ROM with a goniometer and a VAS(0–100 mm) for shoulder pain. Mean differences between affected and non-affected side and mean changes of the slope of the regression line before and after 3 months were studied by paired t-tests.
Results Eight women and 2 men with a unilateral frozen shoulder were included. Mean age was 49.1(sd 5.6) yrs, mean duration of complaints 11.4(sd 8.2) months. Mean active ROM in forward flexion, abduction and external rotation of the frozen shoulder before treatment was 97°(sd 17),75°(sd 21) and 22°(sd 13). Mean scores for pain during movement was 63(sd 25). Mean slopes of the curves of the scapular laterorotation angle in forward flexion, scapular abduction and abduction were 0.725, 0.719 and 0.958 for the affected side and 0.458, 0.504 and 0.494 for the unaffected side, respectively (p < 0.005). After 3 months mean active ROM in the affected shoulder increased to 127°(sd 21) in forward flexion, 127°(sd 33) in abduction and 37°(sd 14) in external rotation (all p < 0.005). Mean pain score decreased to 37 mm (sd 12)(p = 0.013). Mean changes of the slopes were 0.063(p = 0.202), 0.048(p = 0.169) and 0.264(p = 0.008) for forward flexion, scapular abduction and abduction, respectively.
Conclusion This study shows that with a 3-D electromagnetic tracking system the abnormal movement pattern of a frozen shoulder, characterised by the earlier laterorotation of the scapula during shoulder elevation, can be described and quantified. Moreover, the system was sensitive to clinical improvements. Therefore, the system may be a useful tool for the evaluation of treatment of the frozen shoulder. Its value in other shoulder disorders remains to be established.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.