Laterality judgement and tactile acuity in patients with frozen shoulder: A cross-sectional study

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

“…Tactile acuity was altered in the people with frozen shoulder examined in this study with a notably elevated two-point discrimination threshold over the painful frozen shoulder compared to the healthy pain-free shoulder. Our findings agree with a recent similar study [ 42 ] and align with the results of a systematic review examining tactile acuity in people with chronic musculoskeletal pain [ 39 ] which reported diminished acuity in arthritis, complex regional pain syndrome and chronic low back pain. There was no difference in light touch sensation over the affected and unaffected shoulders in our frozen shoulder participants, so the two-point discrimination threshold changes are likely to be of central rather than peripheral origin.…”

“…People with frozen shoulder were slower at recognising images that corresponded to their frozen shoulder compared to images that corresponded to their healthy unaffected shoulder. Our results concur with those of Mena-del Horno et al [ 42 ] and add to the findings of a recent motor imagery in chronic pain systematic review, which reported overall slower RTs of the affected body part in peripheral chronic musculoskeletal pain conditions [ 41 ]. One possible explanation of this poorer motor imagery performance is that the central processing related to implicit motor imagery is affected in people with frozen shoulder, which could reflect maladaptive neuroplastic change.…”

“…Pain related cortical changes can be explored indirectly by motor imagery, one method being the left/right judgement task (LRJT) [ 40 ] requiring activation of proprioceptive, somatosensory, premotor and related regions. Altered motor imagery performance seems to be a feature of a number of chronic pain conditions [ 41 ], but there is uncertainty whether motor imagery performance is altered in people with chronic shoulder pain [ 42 , 43 ]. A second method of exploring pain related somatosensory changes is through tactile acuity testing and the prevailing approach is the two-point discrimination threshold test [ 44 ].…”

“…A second method of exploring pain related somatosensory changes is through tactile acuity testing and the prevailing approach is the two-point discrimination threshold test [ 44 ]. Tactile acuity deficits have been described in a variety of chronic pain conditions, including a recent study in people with frozen shoulder [ 42 ], indicating somatosensory cortex reorganisation in these patients [ 39 ].…”

Peer Review #1 of "Modernising tactile acuity assessment; clinimetrics of semi-automated tests and effects of age, sex and anthropometry on performance (v0.1)"

“…Measures of tactile acuity have been utilised to identify somatosensory impairments in a variety of painful conditions, such as musculoskeletal disorders [1][2][3], chronic pain [4,5], amputation [6,7], neuropathy [8], stroke [9], arthritis [10], complex regional pain syndrome [11] and spinal cord injury [12]. Patients with persistent pain typically demonstrate poorer tactile acuity than healthy controls [4], which is thought to reflect changes in somatosensory processing related to the condition.…”