Radiofrequency evoked potentials: A new window into the nociceptive system.

Objective: To describe the cortical evoked potentials in response to radiofrequency stimulation (RFEPs) in human volunteers.

Methods: Seventeen healthy volunteers participated in an experimental session in which radiofrequency (RF) and electrical (ES) stimulation were applied to the dorsum of the hands and feet. EEG was recorded to evaluate evoked responses for each stimulus modality and stimulation site.

Spatio-temporal modulation of cortical activity during motor deadaptation depends on the feedback of task-related error.

Motor adaptations are responsible for recalibrating actions and facilitating the achievement of goals in a constantly changing environment. Once consolidated, the decay of motor adaptation is a process affected by available sensory information during deadaptation. However, the cortical response to task error feedback during the deadaptation phase has received little attention.

No Evidence of Short-term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients.

Objective: The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain (USP) patients.

Methods: A randomized, double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with USP were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold, glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately, and 72 hours after the intervention in the infraspinatus and deltoid muscles.

Personalized pain management: The relationship between clinical relevance and reliability of measurements.

Reliability is a topic in health science in which a critical appraisal of the magnitudes of the measurements is often left aside to favour a formulaic analysis. Furthermore, the relationship between clinical relevance and reliability of measurements is often overlooked. In this context, the aim of the present article is to provide an overview of the design and analysis of reliability studies, the interpretation of the reliability of measurements and its relationship to clinical significance in the context of pain research and management.

Pressure pain threshold mappings of the infraspinatus muscle in chronic unilateral shoulder pain patients do not reflect generalized hypersensitivity.

Objectives: Increased mechanical sensitivity has been observed on the unaffected side in chronic pain conditions, suggesting generalized or widespread hypersensitivity. However, this cannot be considered as a universal response since this hypersensitivity is inconsistent across muscle pain pathologies. The aim of this study was to assess generalized hypersensitivity in chronic unilateral shoulder pain, using pressure pain threshold (PPT) mappings of the infraspinatus muscle.

A new experimental model of muscle pain in humans based on short-wave diathermy.

Background: Experimental models of pain in humans are crucial for understanding pain mechanisms. The most often used muscle pain models involve the injection of algesic substances, such as hypertonic saline solution or nerve growth factor or the induction of delayed onset muscle soreness (DOMS) by an unaccustomed exercise routine. However, these models are either invasive or take substantial time to develop, and the elicited level of pain/soreness is difficult to control.

Reorganized Force Control in Elbow Pain Patients During Isometric Wrist Extension.

Introduction: Reorganized force control may be an important adaptation following painful traumas. In this study, force control adaptations were assessed in elbow pain patients. Increasing the contraction demand may overcome pain interference on the motor control and as such act as an internal control.

Effects of Prolonged and Acute Muscle Pain on the Force Control Strategy During Isometric Contractions.

Unlabelled: Musculoskeletal pain is associated with multiple adaptions in movement control. This study aimed to determine whether changes in movement control acquired during acute pain are maintained over days of pain exposure. On day 0, the extensor carpi radialis brevis muscle of healthy participants was injected with nerve growth factor (NGF) to induce persistent movement-evoked pain (n = 13) or isotonic saline as a control (n = 13).

Movement Evoked Pain and Mechanical Hyperalgesia after Intramuscular Injection of Nerve Growth Factor: A Model of Sustained Elbow Pain.

Objective: Lateral epicondylalgia presents as lateral elbow pain provoked by upper limb tasks. An experimental model of elbow pain provoked by movement/muscle contraction and maintained over several days is required to better understand the mechanisms underlying sustained elbow pain. This study investigated the time course and pain location induced by nerve growth factor (NGF) injection into a wrist extensor muscle, and whether movement and muscle contraction/stretch provoked pain.

Modulation of motor variability related to experimental muscle pain during elbow-flexion contractions.

Experimental muscle pain typically reorganizes the motor control. The pain effects may decrease when the three-dimensional force components are voluntarily adjusted, but it is not known if this could have negative consequences on other structures of the motor system. The present study assessed the effects of acute pain on the force variability during sustained elbow flexion when controlling task-related (one-dimensional) and all (three-dimensional) contraction force components via visual feedback.

Spatial reorganisation of muscle activity correlates with change in tangential force variability during isometric contractions.

The aim of this study was to quantify the effects of spatial reorganisation of muscle activity on task-related and tangential components of force variability during sustained contractions. Three-dimensional forces were measured from isometric elbow flexion during submaximal contractions (50s, 5-50% of maximal voluntary contraction (MVC)) and total excursion of the centre of pressure was extracted. Spatial electromyographic (EMG) activity was recorded from the biceps brachii muscle.