Twin pregnancy is increasing as infertility treatment is widely given nowadays using assisted reproductive technologies. Twin pregnancy is a risk factor for some complicated pregnancies and it may also cause a hard labor. Although cesarean delivery is frequently indicated in many hospitals in Japan for twin pregnancy in view of the risk of vaginal delivery of the second baby, we have tried vaginal delivery of twin pregnancy in a certain situation. We studied the methods of twin delivery, its outcomes and the early neonatal condition.
  We found 251 twin deliveries (4.6%) in a total of 5,464 deliveries after 22 weeks of pregnancy from January 2005 to December 2009 in the delivery record. Forty-six percent of women pregnant with twins delivered their babies after 33-36 weeks of pregnancy and 41% after 37 weeks of pregnancy. Sixty-five percent delivered by Cesarean section, 33% by vaginal delivery, and 2% vaginally for the first baby and by Cesarean section for the second baby. Fifty percent of the Cesarean deliveries were performed as patients so desired. Ninety women pregnant with twins chose vaginal delivery in which 92% (64/69) of vertex/vertex presentation and 86% (18/21) of vertex/ breech presentation succeeded in vaginal delivery. Neonatal outcome was assessed in 90 vaginally deliveried babies by use of the Apgar scoring system. One-minute Apgar scores of 0-3 (severe asphyxia) were given to 4.5% (8/180) of babies and scores of 4-6 (moderate asphyxia) to 3.3% (6/180) of babies. The incidence meant that a mother had 8.9% and 6.7% of high risk of severe and moderate asphyxia of her babies. But severe asphyxia decreased to 1.7% (3/180), moderate asphyxia to 1.1% (2/180) of babies on the assessment of 5-minute Apgar scores that reflected long-term neonatal outcome. Eleven cases were second babies of all 14 cases of asphyxia on the assessment of 1-minute Apgar scores. In the vaginal delivery group, 5 cases of umbilical cord prolapsed and 3 cases of placental abruption occurred in second babies. In conclusion, twin delivery should be attempted at the birth center where neonatologists and anesthesiologists are available 24 hours as extra-emergency Cesarean delivery can be performed because of the high incidence of emergency Cesarean delivery of second baby (5.6%) and asphyxia of neonates delivered vaginally.

It is well known that eccentric exercise induces muscle damage that is characterized by a prolonged decrease in muscle strength and range of motion, development of delayed onset muscle soreness, and swelling. Therefore, the present study aimed to compare the acute effects of hold-relax stretching (HRS) with those of static stretching (SS) on muscle strength and soreness. The participants comprised 28 male volunteers randomly assigned to either the HRS group (N = 14) or the SS group (N = 14). Initially, the participants of both groups performed 60 maximal eccentric contractions of the knee extensors. Two and four days after this exercise, each group performed either HRS or SS for 60 s at a time and repeated them six times for a total of 360 s. Muscle strength and soreness during stretching and contraction were measured before and immediately after HRS and SS. The results showed that the muscle soreness observed after eccentric contraction significantly decreased immediately after both HRS and SS were performed two and four days later. In addition, there were no significant changes in muscle strength immediately after both HRS and SS were performed two and four days later. The rate of change in muscle soreness after HRS was significantly higher than that after SS two days post eccentric contractions. These results suggest that while both HRS and SS can effectively decrease muscle soreness, the effect of HRS on muscle soreness was larger than the effect of SS.

Resistance training is a treatment for muscle weakness and muscle atrophy. Although previous studies reported that muscle strength increased via changes in neural adaptation after low-intensity resistance training with skin cooling (SC), the effects of the training on both muscle strength and muscle thickness were unclear. Therefore, this study investigated the effect of low-intensity training of the triceps brachii with SC on muscle strength and muscle thickness. Volunteers were 12 healthy men, with one arm randomly assigned to SC and the other to control groups. Elbow extension exercises were performed for 8 weeks, and 1 repetition maximum (RM) and muscle thickness of triceps brachii were measured before and after training. Resistance exercise was performed thrice a week using a dumbbell adjusted to 50％ of 1 RM for both the groups. The SC side used an ice bag secured to the triceps brachii during training. There were no significant interaction effects of 1 RM and muscle thickness of triceps brachii；however, both variables significantly increased after training in both the SC and control groups. Muscle strength and muscle thickness increased after the 8-week training program with SC. No significant differences were observed between the groups.

Resistance training is a treatment for muscle weakness and muscle atrophy. Although previous studies reported that muscle strength increased via changes in neural adaptation after low-intensity resistance training with skin cooling (SC), the effects of the training on both muscle strength and muscle thickness were unclear. Therefore, this study investigated the effect of low-intensity training of the triceps brachii with SC on muscle strength and muscle thickness. Volunteers were 12 healthy men, with one arm randomly assigned to SC and the other to control groups. Elbow extension exercises were performed for 8 weeks, and 1 repetition maximum (RM) and muscle thickness of triceps brachii were measured before and after training. Resistance exercise was performed thrice a week using a dumbbell adjusted to 50％ of 1 RM for both the groups. The SC side used an ice bag secured to the triceps brachii during training. There were no significant interaction effects of 1 RM and muscle thickness of triceps brachii；however, both variables significantly increased after training in both the SC and control groups. Muscle strength and muscle thickness increased after the 8-week training program with SC. No significant differences were observed between the groups.