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INTRODUCTION: Considering the effects of fatigue on athletic performance and the subsequent increase in the probability of injury, the purpose of this study was to compare the effects of slow dynamic, fast dynamic, and static stretching on the recovery of performance, range of motion (ROM), balance, and joint position sense. METHODS: Fifteen collegiate healthy females were involved in four separate sessions of slow dynamic stretching (SDS), fast dynamic stretching (FDS), static stretching (SS), and control condition (CC; without stretching), in a random order with at least 48 h of rest between sessions. After warming up, the individuals performed ROM, balance, joint position sense (JPS) maximum voluntary isometric contraction (MVIC) force as well as countermovement (CMJ) and squat jump (SJ) as pre-tests. After performing the knee fatigue protocol of 4 sets of knee extension and flexion at 60% of 1 repetition maximum (RM) to exhaustion (CC; without stretching) or stretching programs (SDS or FDS or SS), the subjects repeated all the tests at post-test 1 (after 5 min) and post-test 2 (after 60 min). RESULTS: A significantly lower JPS error was detected with SDS while JPS error increased in the SS and control conditions (p < 0.0001). MVIC force significantly increased with SDS and FDS but decreased in control and SS conditions (p < 0.0001). Moreover, a significant decrease in CMJ and SJ height in SS and control conditions was revealed (p < 0.0001). Also, a significant decrease in balance with the control condition was revealed. But only SDS minimized fatigue-induced balance decrements (p < 0.0001). Additionally, the control condition experienced a significant decrease in knee extensor ROM, which contrasted with the significant increase in the quadriceps flexibility with the stretching conditions. CONCLUSIONS: The present results support the idea that SDS may increase quadriceps MVIC force, knee extensor ROM and knee JPS. So according to the present results, it is suggested that the SDS could be implemented and incorporated into a regular recovery program.
RESUMEN
The prevalence of poor response to gonadotropin stimulation is approximately 9-24% in women undergoing in vitro fertilization. Interestingly, due to containing a variety of growth factors, platelet-rich plasma (PRP) can play an important role in tissue regeneration and healing. Thus, in this research, we aimed to investigate the intra-ovarian injection of PRP in women with poor ovarian response. To this goal, 23 poor responders constituted the study population, from among whom 19 women were enrolled. These patients underwent ovarian stimulation according to the Shanghai protocol. Immediately after the first follicular puncture, 2 mL of PRP was injected into each ovary. 1 day after the first puncture and PRP injection, the second stimulation was initiated. Then, oocyte retrieval was followed. About 2-3 months after the first cycle, the patients underwent another treatment with ovarian stimulation according to the Shanghai protocol and then, follicular puncture was performed. The mean numbers of oocytes before and after PRP injection were 0.64 and 2.1, respectively. Two patients experienced spontaneous conceptions. The third case achieved clinical pregnancy and delivered a healthy baby in June 2018. The results of this study appeared to be the first report on the effects of intra-ovarian PRP injection on the increase of ovarian responses, even on the spontaneous conceptions of women with poor ovarian response.