Background Context A subgroup of patients with acute/sub-acute low back pain (LBP) presenting with trunk movement control deficits, pain provocation with segmental testing, and segmental hypermobility have been clinically identified as having movement coordination impairments (MCI) of the trunk. It is hypothesized that these patients have proprioceptive, postural and movement control impairments of the trunk associated with LBP. While, trunk control impairments have been identified in patients with chronic LBP, they have not been investigated in this subgroup or closer to symptom onset. Purpose To identify trunk motor control (postural control and movement precision) impairments in a subgroup of patients with acute/sub-acute LBP who have been clinically identified to have MCI and determine association of these impairments with pain and fear of movement. Study Design/Setting Observational design; University biomechanics lab and clinical practice. Patient Sample Thirty-three patients with acute/sub-acute LBP identified with trunk MCI and 33 gender, age, and BMI matched healthy controls. Outcome Measures Self-report Measures Numeric Pain Rating Scale, Oswestry Disability Questionnaire, Fear Avoidance Beliefs Questionnaire. Physiologic Measures Postural control, Movement precision Methods Center of pressure movement was measured while subjects attempted to volitionally control trunk posture and movement while sitting on a platform with a hemisphere mounted underneath. This created an unstable surface that required coordinated trunk control to maintain an upright-seated posture. Postural control was tested using eyes-open and eyes-closed balance protocols. Movement precision was tested with a dynamic control test requiring movement of the center of pressure along a discrete path. Group trunk motor control performance was compared with ANOVA and t-Test. Performance association with pain and fear of movement were assessed with Pearson’s Correlations. Funding for this study was provided by the National Institutes of Health (xxxxxxx; $xxx,000), with no study specific conflicts of interest to report. Results Patients’ postural control in the eyes closed condition (P=.02) and movement precision (P=.04) were significantly impaired compared to healthy controls, with moderate to large group difference effect sizes. These trunk motor control impairments were not significantly associated with the patients self-reported pain characteristics and fear of movement. Conclusions Patients with clinical identification of trunk MCI demonstrated decreased trunk motor control, suggesting impairments in proprioception, motor output, or central processing occur early in the back pain episode. This information may help to guide interventions to address these specific limitations, improving delivery of care.

ObjectivesGait recovery is an important goal in stroke patients. Several studies have sought to uncover relationships between specific brain lesions and the recovery of gait, but the effects of specific brain lesions on gait remain unclear. Thus, we investigated the effects of stroke lesions on gait recovery in stroke patients.Materials and MethodsIn total, 30 subjects with stroke were assessed in a retrograde longitudinal observational study. To assess gait function, the functional ambulation category (FAC) was tested four times: initially (within 2 weeks) and 1, 3, and 6 months after the onset of the stroke. Brain lesions were analyzed via overlap, subtraction, and voxel‐based lesion symptom mapping (VLSM).ResultsAmbulation with FAC improved significantly with time. Subtraction analysis showed that involvement of the corona radiata, internal capsule, globus pallidus, and putamen were associated with poor recovery of gait throughout 6 months after onset. The caudate nucleus did influence poor recovery of gait at 6 months after onset. VLSM revealed that corona radiata, internal capsule, globus pallidus, putamen and cingulum were related with poor recovery of gait at 3 months after onset. Corona radiata, internal capsule, globus pallidus, putamen, primary motor cortex, and caudate nucleus were related with poor recovery of gait at 6 months after onset.ConclusionResults identified several important brain lesions for gait recovery in patients with stroke. These results may be useful for planning rehabilitation strategies for gait and understanding the prognosis of gait in stroke patients.

Background The prone instability test is used to identify individuals with low back pain (LBP) who would benefit from trunk stabilization exercises. Although activity from muscles during the leg-raising portion of the prone instability test theoretically enhances spinal stiffness and reduces pain, evidence for this is lacking. Objectives To compare and contrast (1) pain and stiffness changes between prone instability testing positions, and (2) muscle activation patterns during the prone instability test leg raise in individuals with and without LBP. Methods Participants with (n = 10) and without (n = 10) LBP participated in this laboratory case-control study. Spinal stiffness was measured using a beam-bending model and 3-D kinematic data. Stiffness changes were compared across the test positions and between groups. Surface electromyographic data were collected on trunk and limb musculature. Principal-component analysis was used to extract muscle synergies. Results Spinal stiffness increased across testing positions in all participants (P<.05). Participants with LBP experienced reduced pain during the test (P<.001). No between-group difference was found in spinal stiffness during leg raising during the test (P>.05). Participants without LBP used 3 muscle synergies during the leg raise and participants with LBP used 2 muscle synergies. Conclusion Spinal stiffness increased in all participants; however, participants without LBP demonstrated a muscle synergy pattern where each synergy was associated with a distinct function of the prone instability test. Participants with LBP used a more global stabilization pattern, which may reflect a maladaptive method of enhancing spinal stability. J Orthop Sports Phys Ther 2019;49(12):899–907. Epub 3 Aug 2019. doi:10.2519/jospt.2019.8577

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