title: Measuring patient confidence and response to different forms of limb feedback during sensorimotor training
title: implications for shoulder rehabilitation
titleType: Subtitle
Creators: name: Shaffer, Michael A
Publisher: name: University of Iowa
Year: 2024
Subjects: Sensorimotor control
Shoulder rehabilitation
Physical Therapy

description: Our long-term goal is to improve physical therapy programs for people with shoulder pathology. To succeed, we need reliable methods to measure pain, function, and lifestyle behaviors (sleep). We explored if physical therapy interventions, even after a single visit, change patient perception. We report, for the first time, excellent reproducibility, and responsiveness of the Modified Outpatient Physical Therapy Improvement in Movement Assessment Log (mOPTIMAL) for people with shoulder pain (Chapter 2).
description: A thorough review of the literature (Chapter 3) helped us better understand the interface between shoulder pathology and sensorimotor control. Shoulder pain can result from improper control of a feed forward mechanism, such as aberrant scapulohumeral rhythm straining subacromial tissues, or an inadequate feedback response, such as stresses on glenohumeral stabilizers when dynamic muscular responses are insufficient to contend with unexpected events. Clinical physical therapy programs have proven successful for improving patient reported outcomes, sometimes irrespective of improvements of movement patterning, while sensorimotor training studies reliably demonstrate reductions of error for target matching tasks. Initial gains in sensorimotor control are believed to result from post-synaptic hyperpolarization with more sustained gains resulting from cortical plasticity.
description: Movement control is commonly assessed as the difference between a target and the user’s limb position and forms the basis for Chapter 4. Reduction of this difference over time, because of training, indicates improvement, or sensorimotor learning. Adding an unexpected, momentary, controlled release of the resistance provides a mechanism to safely study reflexive responses without the co-contractions inherent in studies where the perturbation can be anticipated. We have previously used this concept, error between a visual target and user position, when iii participants replicated sinusoidal flexion/ extension motions at the knee or wrist. Novel to this project is the application of different forms of limb feedback (Visual, Auditory, and or Multimodal- combined auditory and visual) as participants learn a rotational motion of the shoulder.
description: Our results indicate that training which included the user trace, i.e. Multimodal and Visual feedback groups, demonstrated greater reduction of Full Cycle Error when tested immediately after training compared to a group training with only an Auditory indicator of end range. There were no group level differences when assessed one week later. We hypothesized auditory and visual information would be additive during the acquisition phase of sensorimotor learning and, as such, Multimodal training would yield the greatest reduction for tracking error. By contrast, we expected Multimodal feedback, and the potentially overwhelming coupling of visual and auditory information, to impede learning feedback responses to unexpected events. We seem to have overestimated the positive and negative effects of combining visual and auditory feedback as Multimodal training was not superior to Visual feedback alone for feed forward control (Full Cycle Error and 50-100ms Non-Perturbation Trials) and was not the detriment to learning post-perturbation responses (50-100ms Perturbation Trials and Peak User Rate) that we expected. Peak User Rate was slower at 7 Day Post Test compared to Baseline indicating participants were better able to contend with the unexpected perturbation after training. All markers of sensorimotor control demonstrated greater improvement 7 Days Post training compared to Immediate Post training values with significant improvements for feed forward control (Full Cycle Error). This indicates that the nervous system continues amplifying neural networks activated during training for at least one week.
description: We believe this project sets the stage to assess the sensorimotor control of patients with shoulder pathology, track their improvements resulting from varied practice regimens, and correlate those changes to patient reported outcome measures such as the mOPTIMAL.