The inter- and intra-individual variance in descending pain modulation evoked by different conditioning stimuli in healthy men.

Background and purpose Conditioned pain modulation (CPM) is a phenomenon in which pain is inhibited by heterotopic noxious stimulation. It is not known how the experimental condition affects the magnitude of the CPM response and the inter-and intra-individual variations. It is important to get the information of the test-retest reliability and inter-individual variations of CPM to apply CPM as a diagnostic tool or for screening analgesic compounds.

Effects of continuous fascia iliaca compartment blocks for postoperative analgesia in patients with hip fracture.

Background: Effective analgesia is essential for the postoperative care of orthopedic patients.

Objectives: To evaluate the efficacy of continuous fascia iliaca compartment block (FIB) as postoperative analgesia after hip fracture surgery, and to compare FIB with patient-controlled intravenous analgesia (PCIA) using fentanyl for 48 h postoperatively.

Methods: Patients with hip fractures who were scheduled for open reduction and internal fixation surgery using the antirotation proximal femoral nail technique were randomly assigned to the FIB or PCIA groups.

Pain and cognitive dysfunction are the risk factors of delirium in elderly hip fracture Chinese patients.

Aims: To observe the incidence of delirium in elderly hip fracture patients and search for the potential risk factors.

Methods: Patients over 60 years were included in this study. Gender, age, education level, fracture type, organic dysfunction, cognitive dysfunction, comorbidity, medication, time from admission to surgery, and pain intensity were collected and analyzed, together with laboratory assessments and surgery including surgery type, time in surgery and blood loss in surgery.

Local pain and spreading hyperalgesia induced by intramuscular injection of nerve growth factor are not reduced by local anesthesia of the muscle.

Objectives: Injections with local anesthesia for therapeutic and diagnostic purposes are common clinical practice. This double-blind placebo controlled study explores the rational of local anesthetic blocks for the detection of muscle pain as the primary generator in spreading hyperalgesic conditions.

Methods: Experimental muscle pain was induced by injections of nerve growth factor (NGF) in the left and right supraspinatus muscle of 11 healthy volunteers.

Sensitization in patients with painful knee osteoarthritis.

Pain is the dominant symptom in osteoarthritis (OA) and sensitization may contribute to the pain severity. This study investigated the role of sensitization in patients with painful knee OA by measuring (1) pressure pain thresholds (PPTs); (2) spreading sensitization; (3) temporal summation to repeated pressure pain stimulation; (4) pain responses after intramuscular hypertonic saline; and (5) pressure pain modulation by heterotopic descending noxious inhibitory control (DNIC). Forty-eight patients with different degrees of knee OA and twenty-four age- and sex-matched control subjects participated.

Contribution of the local and referred pain from active myofascial trigger points in fibromyalgia syndrome.

The generalized hypersensitivity associated with fibromyalgia syndrome (FMS) may in part be driven by peripheral nociceptive sources. The aim of the study was to investigate whether local and referred pain from active myofascial trigger points (MTrPs) contributes to fibromyalgia pain. FMS patients and healthy controls (n=22 each, age- and gender-matched) were recruited.

Spatial and temporal summation of pain evoked by mechanical pressure stimulation.

Chronic pain patients often suffer from widespread and long lasting pain. The integrative effect of combined spatial and temporal summation on pain intensity has not been quantitatively tested. The present study was designed to investigate: (1) if the size of the stimulation area would facilitate the temporal summation of pain to repetitive pressure stimulation, and (2) if temporal summation is effective when stimulating separated sites, repetitively.

Temporal summation of pressure pain during muscle hyperalgesia evoked by nerve growth factor and eccentric contractions.

Nerve growth factor (NGF) has a key role in the generation and potentiation of pain. Its centrally sensitizing effects may facilitate pain responses to noxious stimulus. This study assessed (1) the influence of NGF on delayed onset muscle soreness (DOMS) in shoulder muscles; and (2) the temporal summation of pressure pain during hyperalgesia induced by NGF and DOMS.

Gender effects on trapezius surface EMG during delayed onset muscle soreness due to eccentric shoulder exercise.

The purpose of this study was to investigate gender-specific motor control strategies during eccentric exercise and delayed onset muscle soreness (DOMS) in the shoulder region. Twelve healthy males and females participated in the study. Eccentric shoulder exercises were conducted on the dominant shoulder while the other side served as control.

Enhanced temporal summation of pressure pain in the trapezius muscle after delayed onset muscle soreness.

Temporal summation of muscle pain is an important factor in musculoskeletal pain as central integration of repetitive nociceptive input can be facilitated in musculoskeletal pain patients. The aim of this study is to evaluate changes in temporal summation of pressure pain after induction of delayed onset muscle soreness (DOMS) of the trapezius muscle. Sixteen healthy volunteers participated in the study.

Dynamic shoulder dynamometry: a way to develop delay onset muscle soreness in shoulder muscles.

A dynamic shoulder dynamometer has been designed to develop a vertical downward force over a measured range of motion, i.e. scapular elevation.

Delayed onset muscle soreness in neck/shoulder muscles.

The aim of the present study is to: (1) induce delayed onset muscle soreness (DOMS) in the neck and shoulder muscles; (2) compare the pressure pain sensitivity of muscle belly with that of musculotendinous tissue after DOMS; (3) examine the gender differences in the development of DOMS. An eccentric shoulder exercise was developed to induce DOMS on neck/shoulder muscles using a specially designed dynamometer. Eccentric shoulder contraction consisted of 5 bouts, each bout lasted 3min, with 3min rest period between each bout.

Temporal summation of pain evoked by mechanical stimulation in deep and superficial tissue.

Unlabelled: Temporal summation of deep tissue pain has been suggested to be facilitated in chronic musculoskeletal pain syndromes. This study aimed to test whether temporal summation of mechanical induced pressure pain is (1) more pronounced at short (1 second) interstimulus intervals (ISIs) compared with long ISI (30 seconds), (2) more potent than summation elicited by pure skin stimulation, and (3) attenuated in women compared with men. Twelve age-matched men and 12 women were included.