트레드밀 전,후방보행 훈련이 탈진적 운동 수행 전과 후의 하지 근력에 미치는 영향

류호열 ( Ho Youl Ryu ),윤범철 ( Bum Chul Yoon ),박성규 ( Sung Kyu Park ),박해찬 ( Hae Chan Park ),윤성진 ( Sung Jin Yoon ) 대한스포츠의학회 2010 대한스포츠의학회지 Vol.28 No.1

The purpose of this study was to investigate the physiological effects of forward and backward walking training on lower extremity muscle strength before and after exhausting exercise. Fourteen healthy male adults were randomly divided into backward walking (BW, n=7) and forward walking (FW, n=7) training groups. Each group took part in pre-test consisted of knee extensor and flexor isokinetic peak torque (PT), total work (TW), electromyography (EMG) before and after exhausting exercise. Exhausting exercise was used to measure lower extremity endurance, which is incremental treadmill running using the Bruce protocol. The BW and FW training groups participated in a 6 weeks training program, consisted of 3 sessions per week for a total of 18 sessions. After finishing the training program, the post-test was performed using the same method. BW training group showed significant increases in knee extensor/flexor PT (4.6%/13.9%), TW (17.34%), EMG (35.9%) before exhausting exercise and PT (23.9%/ 18.8%), TW (46.7%), EMG (59.8%) after exhausting exercise. But FW training group did not show a significant increase in knee extensor/flexor PT (0.1%/3.2%), TW (1.8%), EMG (10.9%) before exhausting exercise and PT (2%/1%), TW (5.6%), EMG (17.2%) after exhausting exercise. BW training has positive effects on lower extremity muscle strength, especially muscle endurance that is important to prevent muscle weakness during competitive sports.

만성 심부전 환자의 운동부하 심폐기능 평가 중단 원인에 따른 호흡가스 변인 분석

류호열(Ho Youl Ryu),오재원(Jaewon Oh),김인철(In-Cheol Kim),윤도은(Do Eun Yun),김지수(Ji Soo Kim),김수경(Soo Kyung Kim),강석민(Seok-Min Kang) 대한심장호흡물리치료학회 2016 대한심장호흡물리치료학회지 Vol.4 No.1

Purpose : The purpose of this study is to investigate cardiorespiratory parameters according to the termination reasons of graded exercise test in patients with chronic heart failure (CHF). Methods : The study population consisted of 116 patients with CHF (74.1% male, age 62 ± 10 years old). Each subject safely finished cardiopulmonary exercise test (CPET) without symptom limited emergency stop such as ventricular tachycardia or syncope, or chest pain. The CPET parameters were collected from Mar. 2014 to Feb. 2016. The reasons for test termination were subdivided into 3 groups: test end (9.5%, n=11); dyspnea (56%, n=65); leg pain & fatigue (34.5%, n=40). Results : The patients with leg pain & fatigue are older than those with dyspnea and test end (66 ± 10 vs. 61 ± 9 vs. 55 ± 7 years old, respectively, p=0.001), The HF patients with leg pain & fatigue showed lower peak VO 2 (18.9 ± 4.3 vs. 23.9 ± 4.4 vs. 31.6 ± 5.5 ml·kg -1 ·min -1 , respectively, p<0.001), higher VE/VCO 2 (35.5 ± 5.5 vs. 30.8 ± 4.4 vs. 29.1 ± 5.4, respectively, p<0.001) and higher prevalence of poor effort (respiratory exchange ratio, RER<1.1, 57.5% vs. 36.9% vs. 18.2%, respectively, p=0.028) than those with dyspnea and test end. Conclusion : Patients who terminated exercise due to leg pain & fatigue showed decreased exercise capacity which further leads to underestimation of cardiopulmonary function compared to other reasons. Thus, healthcare providers should evaluate patient’s underlying skeletal muscular diseases to provide comprehensive cardiac rehabilitation such as pain control and individualized leg muscle endurance training program.

정상인에서 리컴번트(recumbent)와 직립(upright) 사이클 운동의 심폐반응 비교

류호열(Ho-Youl Ryu),이중희(Ho-Youl Ryu),윤종찬(Jong-Chan Youn),도일선(Il-Sun Do),윤도은(Do-Eun Yun),강석민(Seok-Min Kang) 대한심장호흡물리치료학회 2014 대한심장호흡물리치료학회지 Vol.2 No.1

Purpose : The purpose of this study is to compare cardiopulmonary exercise parameters during recumbent cycling(RC) and upright cycling(UC) in healthy subjects. Methods : The study population consisted of 12 healthy volunteers(male=7, mean age 29.7±5.7, female=5, 25.4±2.9 years old). Each subject was randomly assigned to perform RC or UC, and started workload at 10 watt and increased by maximal pedaling(to 100 watt). After taking a rest during 1 week, they performed cycling vice versa. Results : Baseline parameters including heart rate(HR), systolic blood pressure(SBP) and rate pressure product(RPP) are comparable between RC and UC group. Submaximal SBP(138.1±10.8 vs. 151.3±15.9 mmHg, p=0.027), submaximal RPP (15244.2±1860.8 vs. 17698.8±3325.4, p=.036), and maximal RPP(25328.3±3032.9 vs. 28443.8±3139.4, p=.022) in RC group were significantly lower than those of UC group. Peak VO 2 in RC group tends to be lower than UC group(27.2±3.6 vs. 29.5±2.8 mL/kg/min, p=.087). Conclusion : With similar exercise intensity, RC showed less cardiopulmonary stress compared with UC. These results provide the feasibility of RC based cardiac rehabilitation program in patients with heart failure or in elderly.

후방보행 훈련이 하지 등속성 근력 및 내측광근 표면 근전도에 미치는 영향

류호열 ( Ho-youl Ryu ) 대한신경치료학회 2010 신경치료 Vol.14 No.1

Purpose Backward walking exercise is being recommended for increasing lower extremity strength, especially vastus medialis strength. But little research has been conducted backward walking training to clarifying vastus medialis strength. The purpose of this study is to verify the effectiveness of backward walking training on knee muscle strength especially vastus medialis strength. Subjects and Methods Fourteen healthy male adults were randomly divided into backward walking (BW, n=7) and forward walking (FW, n=7) training groups. Each group took part in muscle strength tests of knee extension and flexion isokinetic peak torque (PT), total work (TW). Vastus medialis (VM) and vastus lateralis (VL) root mean square (RMS) of electromyographic (EMG) also measured during maximal voluntary isometric contraction. Each group took one week resting period and then, performed BW and FW training program for 6 weeks, consisting of 3 sessions per week for a total of 18 sessions. The training intensities applied to individual subjects were at 65% of their VO2max respectively. Results The BW training group showed a significant increases in knee extension and flexion isokinetic PT (4.6%, 13.9%), isokinetic TW (17.34%), and isometric VM EMG RMS (48.5%). But FW training group did not show a significant increase in any of the items. Conclusion BW training has positive effectiveness on knee muscle strength, especially vastus medialis strength, which is acting as medial stabilizer of the patella.

만성 심부전 환자의 심장이식 수술 전 하지 근력 및리컴번트 사이클링 운동 프로그램의 효과 대

류호열(Ho-Youl Ryu),오재원(Jaewon-Oh),윤도은(Do-Eun Yun),김지수(Ji-Soo Kim),김수경(Soo-Kyung Kim),강석민(Seok-Min Kang) 대한심장호흡물리치료학회 2017 대한심장호흡물리치료학회지 Vol.5 No.1

Purpose : Muscle weakness, especially leg muscle is the key characteristic that can be found in heart failure(HF) patients who are waiting for heart transplantation(HT) for a long time. Exercise training before HT is important to reverse muscular de-conditioning that place HT recipients at increased cardiovascular risk. The purpose of this study is to investigate the effect of lower extremity strengthening and recumbent cycle aerobic exercise program on muscular fitness in HF patients prior to HT. Methods : Each subject completed at least 24 sessions of lower extremity strengthening exercise(leg press 20 min / 1 session) and recumbent cycle aerobic exercise (20 min / 1 session) at Severance cardiac wellness center who was hospitalized waiting for HT. Knee extensor maximal voluntary isometric strength (MVIC), mean muscle power (MMP) and 6 minutes walking distance (6 MWD) were recorded at baseline (D1), and at the end of 24 training sessions (D2), and at discharge date after HT (D3). Results : The study population consisted of 8 HF patients (7 male, 35±19 years old, mean EF=18.3±6.4%). All subjects completed at least 24 training session with no adverse events. The MVIC (403.9±73.9 vs. 478±76.9 N, p=0.001), MMP (155.5±57 vs. 186.7±65 watt, p=0.003), and 6 MWD (441.6±64.9 vs. 520.3±53.9 m, p=0.002) measured at D2 were significantly increased compared with baseline, respectively. However, the MVIC (478±76.9 vs. 398±97.4 N, p=0.032) and MMP (186.7±65 vs. 145.5±77.6 watt, p=0.015) measured at D3 were significantly decreased compared with D2, whereas 6 MWD (520.3±53.9 vs. 520.7±35.4 m, p=0.708) were not different significantly. MVIC and MMP showed not significant differences compared D1 with D3, but 6 MWD (441.6±64.9 vs. 520.7±35.4 m, p=0.011) was improved significantly. Conclusion : Our study showed that lower extremity muscle strengthening and aerobic recumbent cycling exercise program prior to HT can improve HF patient’s muscular fitness and 6 MWD.

남성 심부전 환자의 넙다리 네갈래근 근력이 최대 유산소 능력과 재입원에 미치는 영향

류호열(Ho-Youl Ryu),송중섭(Jung-Sub Song),최경욱(Kyoung-wook Choi) 대한심장호흡물리치료학회 2022 대한심장호흡물리치료학회지 Vol.10 No.1

Purpose: The cardiopulmonary exercise test (CPET) is widely used to evaluate the clinical prognosis in patients with heart failure (HF). However, some patients with HF cannot perform CPET at maximal exercise intensity because of unstable medical condition or musculoskeletal problems. Thus, the study aimed to investigate the effects of quadriceps maximal voluntary isometric contraction (Q-MVIC) strength on aerobic capacity and re-hospitalization (RH). Methods: Patients with HF (n = 60, 59.03 ± 13.4 years, male 100%) were recruited in this study. We evaluated the Q-MVIC strength and aerobic capacity after discharge from hospitalization and followed up the RH rate during home-based self-care periods. Results: The RH (n = 15, 64.00 ± 14.69) group showed significantly lower Q-MVIC strength (p = .028) than the no RH(NRH, n = 45, 57.78 ± 13.15) group. In addition, the RH group showed significantly lower peak VO2 (p < .001) than the NRH group. Moreover, the Q-MVIC strength and peak VO2 demonstrated significant correlation (r = .414, p < .001). Conclusion: Our study showed that the knee extensor strength has strong predictive values on aerobic capacity and RH rate in patients with HF.

박출률 감소 심부전 환자에서 리컴번트 사이클 운동의 안전성과 훈련 효과

송중섭(Jung-Sub Song),류호열(Ho-Youl Ryu),강석민(Seok-Min Kang) 대한심장호흡물리치료학회 2020 대한심장호흡물리치료학회지 Vol.8 No.1

Purpose : Higher levels of peak oxygen consumption and maximal aerobic capacity in patients with heart failure (HF) can lead to improvement of clinical outcomes such as morbidity and mortality. For this reason, cardiac rehabilitation (CR) should be applied to maximize HF patients’ aerobic capacity. However, several precautions are necessary due to unexpected cardiac adverse events in case of HF with reduced ejection fraction (HFrEF). The purpose of this study is to investigate the effect and safety of recumbent cycle exercise and regular training in order to apply a CR program for HFrEF patients. Methods : 72 HFrEF patients completed a cardiopulmonary exercise test and a knee extensor maximal voluntary isometric contraction (MVIC) and muscle power (MP) test at baseline. 12 HFrEF patients completed recumbent cycle exercise training (50 minutes, three times per week) for 24 sessions, followed by a post-test. Results : The study population consisted of 12 HFrEF patients (age 57.5± 10.8 years, all male). All subjects completed 24 training session without adverse events. Compared to baseline, the peak VO2 and six minute walking distance were significantly improved by 16% (p=0.003) and 18% (p<0.001) respectively. Knee extensor MVIC and MP weresignificantly improved by 18% (p=0.002) and 21% (p=0.012) respectively. Conclusion : Our study showed that recumbent cycle exercise could be an effective and safe exercise training method to increase aerobic capacity and leg muscle strength in HFrEF patients.