Changes in the Linear Relationship between Muscle Contraction Intensity and Muscle Hardness after Rectus Femoris Muscle Strain.

OBJECTIVE: Joint torque differences between healthy and rehabilitated legs are often measured as a clinical index of recovery from muscle strain injury. Unfortunately, it should be noted that this is a questionable evaluation measure of the muscle after injury because it is a composite value including related cooperating muscles. Meanwhile, the use of ultrasound elastography for the measurement of individual muscle mechanical properties (i.e., muscle hardness) has recently expanded. The purpose of this study was to examine, using ultrasound elastography, the differences in the linear relationship between muscle contraction intensity and muscle hardness during knee extension in athletes who had recovered from grade II rectus femoris muscle strain injury through comparison of the healthy and rehabilitated legs. METHODS: Six athletes participated. Rectus femoris muscle hardness, determined during isometric contraction at 10%, 20%, 30%, and 40% of maximum voluntary contraction, was evaluated using ultrasound strain elastography. RESULTS AND CONCLUSION: The results indicated that for the healthy legs, the strain ratios, as indicated by muscle hardness, decreased linearly (became harder) with contraction intensity, but the strain ratios for the rehabilitated legs decreased nonlinearly. These results show the danger of judging the recovery period using only the difference between healthy and rehabilitated muscle strengths and the importance of evaluating individual muscles.

Associations between pain drawing and psychological characteristics of different body region pains.

BACKGROUND: Pain drawings have frequently been used for documentation of pain and a convenient diagnosis tool. Pain drawings were found to be associated with psychological states in chronic patients with low back pain. Few researchers have investigated pain drawings except in low back pain. The aim of this study was to investigate the pain, pain drawings, psychological characteristics, and pain interference in the head, neck-shoulder (NS), and low-back/lower-limb (LB-LL) regions among patients with chronic pain. METHODS: We included a total of 291 patients with new chronic pain (headache, 62; NS pain, 87; LB-LL pain, 142). The pain drawings and scores of 10-cm Visual Analogue Scale (VAS), Hospital Anxiety and Depression Scale (HADS), Pain Catastrophizing Scale (PCS), Short-Form McGill Pain Questionnaire (SF-MPQ), and Pain Disability Assessment Scale (PDAS) were extracted from medical records. A subset of 60 pain drawings was scored by senior and junior evaluators to assess inter-rater agreement. We investigated the correlation between pain drawings and VAS, HADS, PCS, SF-MPQ, and PDAS in each body region group at the initial visit. Moreover, almost all patients received nonsurgical treatment as a follow-up and were investigated using VAS after treatment. RESULTS: The reliability of pain drawings was substantial with an interevaluator reliability in headache, NS, and LB-LL pain. Nonorganic pain drawings were associated with psychological disturbances in NS and LB-LL pain, but not headache. Poor outcomes were associated with nonorganic drawings in LB-LL pain, but not in the case of headache or NS pain. CONCLUSIONS: Our results suggest that the characteristics of patients with nonorganic drawings differ according to body regions.

No effects of pulsed electromagnetic fields on expression of cell adhesion molecules (integrin, CD44) and matrix metalloproteinase-2/9 in osteosarcoma cell lines.

Pulsed electromagnetic fields (PEMF) could enhance the cytocidal effects of chemotherapeutic drugs on malignant tumor cell lines, but metastasis effects of PEMF on tumor cells have not been investigated. We investigated the effects of PEMF exposure on the expression levels of some metastasis-related molecules, including integrin α subunits (α1, α2, α3, α4, α5, α6, αv), integrin ß subunits (ß1, ß2, ß3, ß4), CD44, and matrix metalloproteinase-2/9 (MMP-2/9) in four human osteosarcoma cell lines (HOS, MG-63, SAOS-2, NY) and two mouse osteosarcoma cell lines (DOS, LM8) by using FACScan analysis, gelatin zymography, and Western blot analysis. Our results indicate that PEMF exposure has no effect on the expression of some molecules that are associated with tumor cell invasion and metastasis, and therefore suggest that PEMF exposure may be safely applied to chemotherapy for osteosarcoma.

The effect of acupressure at the extra 1 point on subjective and autonomic responses to needle insertion.

BACKGROUND: Premedication with sedatives can decrease the discomfort associated with invasive anesthetic procedures. Some researchers have shown that acupressure on the acupuncture extra 1 point is effective for sedation. We investigated whether acupressure on the extra 1 point could alleviate the pain of needle insertion. METHODS: We investigated the effect of acupressure at the extra 1 point or a sham point on needle insertion using verbal rating scale (VRS) pain scores and heart rate variability (HRV). Twenty-two healthy female volunteers were randomly allocated to two groups: the extra 1 group received acupressure at the extra 1 point, and the sham group received acupressure at a sham point. After starting the electrocardiogram record, a 27-gauge needle was inserted into the skin of a forearm. Thereafter, another needle was inserted into the skin of the other forearm during acupressure. RESULTS: Acupressure at the extra 1 point significantly reduced the VRS, but acupressure at the sham increased the VRS. Acupressure at the extra 1 significantly reduced the low frequency/high frequency ratio of HRV responding to needle insertion. CONCLUSIONS: Acupressure at the extra 1 point significantly reduced needle insertion pain compared with acupressure at the sham point. Also, acupressure at the extra 1 point significantly reduced the low frequency/high frequency ratio of HRV responding to needle insertion, which implies a reduction in sympathetic nervous system activity.