This study investigated the changes in muscle thickness of transversus abdominis (TrA) during trunk muscle training. The subjects comprised 30 young men (average age 20.1 SD1.6 years) without low back pain. The muscle thickness of the upper region of TrA, middle region of TrA and lower region of TrA were measured by B-mode ultrasound. Muscle thickness were measured at rest and during the following 5 exercises; abdominal drawing, curl up, trunk ipsilateral rotation, trunk contralateral rotation and both straight leg raise in supine. There were no significant differences in the muscle thickness of the upper region of TrA between resting condition and all exercises. Muscle thickness during drawing, curl up and ipsilateral rotation were significantly greater than that at rest in middle region of TrA, and the rate of change in muscle thickness was the largest for drawing. Muscle thickness during drawing, curl up and ipsilateral rotation were significantly greater than that at rest in the lower region of TrA, and the rate of change in muscle thickness was the largest for ipsilateral rotation. These results suggested that the changes in muscle thickness of TrA during trunk muscle training showed different patterns depending on the region of TrA.

Introduction: There has been no case report in which hyperpigmentation developed on the skin area where a transdermal fentanyl patch was applied in a patient. Case report: A 43-year-old man with recurrence of postoperative rectal cancer was treated by cetuximab plus irinotecan and panitumumab plus FOLFIRI. For cancer pain, transdermal fentanyl patch (Fentos®) was administered, and radiation from behind was performed. Hyperpigmentation then appeared on the chest and the abdominal skin sites where the patches were applied. The hyperpigmentation nearly disappeared four months after the fentanyl patch was discontinued. Discussion: The cause of the pigmentation was possibly due to post inflammatory hyperpigmentation secondary to contact dermatitis. It was desirable to conduct patch test and skin biopsy for making an accurate diagnosis. Conclusion: We should pay a careful attention to hyperpigmentation of the skin where a transdermal fentanyl patch is applied.