Earticle

Purpose: This study aimed to investigate the immediate effect of dynamic or static stretching applied to the ankle on the balance ability to effectively guide exercise within a limited time of treatment in clinical practice. Methods: Twenty healthy adults aged 23.32±2.23 were divided randomly into two groups. Control group performed static stretching three times for 30 seconds and the experimental group performed dynamic strethcing three times. Balance ability was measured before and after the intervention in each group and the results were anlayzed using paired and independent t-test. Results: As a result, there was no significant differences between static and dynamic stretching in both groups. However, there was a margianl signifcantly changes in balance ability within dynamic strethcing group. Conclusion: The results of this study indicated that future studies with longer intervention period and lager sample size will be needed to provide more accurate and objective evidences, considering that a margnial significant changes was found in the dynamic stretching group.

Performing warm-ups increases muscle temperature and blood flow, which contributes to improved exercise performance and reduced risk of injuries to muscles and tendons. Stretching increases the range of motion of the joints and is effective for the maintenance and enhance-ment of exercise performance and flexibility, as well as for injury pre-vention. However, stretching as a warm-up activity may temporarily de-crease muscle strength, muscle power, and exercise performance. This study aimed to clarify the effect of stretching during warm-ups on mus-cle strength, muscle power, and muscle endurance in a nonathletic population. The subjects of this study consisted of 13 physically active male collegiate students with no medical conditions. A self-assessment questionnaire regarding how well the subjects felt about their physical abilities was administered to measure psychological readiness before and after the warm-up. Subjects performed a non–warm-up, warm-up, or warm-up regimen with stretching prior to the assessment of the isokinetic moments of knee joints. After the measurements, the respec-tive variables were analyzed using nonparametric tests. First, no statis-tically significant intergroup differences were found in the flexor and extensor peak torques of the knee joints at 60˚/sec, which were as-sessed to measure muscle strength. Second, no statistically significant intergroup differences were found in the flexor and extensor peak torques of the knee joints at 180˚/sec, which were assessed to measure muscle power. Third, the total work of the knee joints at 240°/sec, in-tended to measure muscle endurance, was highest in the aerobic-stretch-warm-ups (ASW) group, but no statistically significant differ-ences were found among the groups. Finally, the psychological readi-ness for physical activity according to the type of warm-up was signifi-cantly higher in ASW. Simple stretching during warm-ups appears to have no effect on variables of exercise physiology in nonathletes who participate in routine recreational sport activities. However, they seem to have a meaningful effect on exercise performance by affording psy-chological stability, preparation, and confidence in exercise perfor-mance.

This study aimed to compare the effects of two latissimus dorsi muscle (LD) stretching exercises on the shoulder joint flexion angle, LD muscle tone, and thoracic mobility in subjects with short LD. This was a cross-sectional and randomized controlled trial. The study included 28 subjects with a short LD. Participants showing a range of shoulder flexion of <170° in the LD length test were identified as having a short LD. The subjects were randomly assigned to either Group 1 (shoulder abduction + contralateral trunk side bending) or Group 2 (shoulder abduction + shoulder external rotation). LD muscle tone and stiffness were measured using Myoton PRO. Thoracic mobility of the middle part was measured using a circular tape measure. Both groups 1 and 2 showed significantly increased range of shoulder flexion and middle thoracic mobility, and the LD muscle tone of the distal and lower parts and LD muscle stiffness of the distal parts decreased significantly after interventions (p<.05). In the comparison between groups, no significant differences were noted in all dependent variables. Therefore, this study suggests that both LD stretching exercises can be effective in increasing the range of shoulder flexion, reducing LD muscle tone and stiffness, and improving chest mobility.

Purpose: The purpose of this study is to examine the effects of flexibility and balance when stretching after attaching tape. Methods: Twenty-five college students who reduced their hamstring numbers participated in the experiment. The experimental group was taping and the control group was not taping. Stretching took place in four sets for 15 seconds, with each set resting for 30 seconds. Flexibility was used to measure the flexibility of short hamstring using a smartphone application called the Clinometer application. We used a Biodex balance system to measure balance. Immediately before stretching, immediately after stretching, and 6 minutes later, a total of 3 measurements were made. We used two-way repeated ANOVA to identify significant differences. Results: When measured immediately before stretching, immediately after stretching, and 6 minutes, both groups showed increased flexibility and sense of balance. There was no statistically significant difference in balance sensation with taping attachment. There was a statistically significant difference in the flexibility change with taping attachment. (p<0.05) Conclusion: Regardless of the taping attachment to the short hamstring, flexibility and balance were positively affected by stretching. However, statistical flexibility was improved when stretching was applied after taping.

본 연구에서는 스트레칭 전후 머리척추각 변화와 스트레칭 후 휴식 시간 경과에 따른 근긴장도 변화를 알고자 하였다. 건강한 20-30대 남녀 학생 57명을 대상으로 하였고, 머리척추각은 스트레칭 전과 후를 비교하였 다. 스트레칭은 정적 수동 스트레칭을 적용하였고, 30초 실시 후 휴식 시간 10초로 총 3회 반복하였으며, 근긴장도 측정 장비를 사용하여 스트레칭 전, 직후, 2분 후, 5분 후를 측정하였다. 스트레칭 전후의 머리척추각은 결과적으로 유의한 차이가 없었으며, 스트레칭 후 휴식 시간에 따른 근긴장도 변화는 스트레칭 전보다 5분 후가 더 유의한 차이를 보였다. 스트레칭을 실시한 직후에 바로 신체활동을 하는 것보다는 적어도 5분 이상의 휴식을 취하여 근긴 장도를 낮춘 후 활동하는 것이 보다 효과적이다.

In this study, we wanted to know the change in the craniovertebral angle before and after stretching and muscle tone according to rest time immediately after stretching. 57 students in their 20s and 30s were targeted, and the craniovertebral angle was compared before and after stretching. Static manual stretching was applied for stretching, and after 30 seconds, it was repeated three times with a break time of 10 seconds, and before stretching, immediately after, two minutes after, and five minutes after stretching were measured using muscle tone measuring equipment. As a result, there was no significant difference in craniovertebral angle before and after stretching, and the change in muscle tone according to the rest time after stretching was more significant after 5 minutes than before stretching. It is more effective to take five minutes to rest after stretching, reduce muscle tone than working immediately after stretching.

In order to conduct a study on the importance of the wrist joint, which causes a lot of pain among middle-aged people, in relation to work related to musculoskeletal disorders, the effect of stretching on grasping power was studied. In order to compare the grasping power of the wrist for middle-aged people in their 50s, the experiment was conducted by comparing before and after the wrist joint motion stretching. According to the experimental results of wrist gripping power for the control group and the experiment group on wrist gripping power, it was investigated that stretching did not change much in increasing wrist gripping power, but stretching application had an effect on wrist gripping power. In terms of preventing musculoskeletal accidents, reducing pain due to degenerative diseases, and preventing accidents, stretching seems to have an effect when approaching, so it is considered that continuous stretching before and after work is necessary. Therefore, it is suggested that stretching time secured quantitatively through safety and health education before work is necessary.

본 연구는 Myoton Pro Digital Palpation의 근활성도 측정 장비를 활용하여 근육의 변화와 관련된 정량 적인 정보를 제공받고 스트레칭 복합 운동 프로그램 적용시 근 활성도에 영향을 미치는 변인들을 분석 하는데 목적을 두고 연구하였다. 첫째, 근 긴장도 측정을 통해서 근육의 반사적 자극이 반영된 신장에 대한 저항을 분석할 수 있었고, 전경골근(왼쪽), 대퇴이두근(외쪽)의 왼쪽 근육을 제외하고 상승된 변화를 보였다. 둘째, 근 경직도 측정을 통해서 외력에 대한 조직의 저항에 필요한 힘의 강도를 분석할 수 있었고, 대 퇴직근(왼발), 대퇴이두근(외쪽)의 왼발 근육을 제외하고 상승된 변화를 보였다. 셋째, 근 탄성도 측정을 통해서 근 수축이나 외부 힘이 제거된 후 근 진폭의 감쇠율 분석을 하였고, 대퇴직근(오른발), 비복근(양발)을 제외하고 상승된 변화를 보였다. 넷째, 근 회복시간 측정을 통해서 근 수축이나 외부 힘이 제거된 이후 처음 상태로 돌아오는데 소요되 는 시간을 분석하였고, 외측광근(양발), 대퇴직근(오른발), 대퇴이두근(외쪽)의 왼발을 제외하고 감소된 변 화를 보였다. 향후 근활성도 측정 장비를 활용하여 다양한 형태의 훈련프로그램, 종목별 장비 활용의 유무, 자세의 변형에 따른 비교분석을 통해서 근육의 다양한 변화 등을 정량적으로 측정하여 자세 안전성, 운동기능 향상, 재활치료 등의 측면에서 정보를 제공할 수 있다고 사료된다.

Objectives The purpose of this study is to provide quantitative information related to muscle changes through a measuring device called Myoton Pro and to analyze factors affecting muscle activity through various exercise programs. Methods Through a stretching complex exercise, the vastus medialis, vastus lateralis, rectus femoris, tibialis anterior, gastrocnemius, and biceps femoris were measured three times and quantified as the average value. Measurements were made by contacting the probe of the measuring device at a right angle to the muscle surface. Results Muscle tone analysis showed elevated changes except for the left muscles of the tibialis anterior (left) and biceps femoris (lateral).Muscle stiffness analysis showed elevated changes except for the left foot muscles of the rectus femoris (left foot) and biceps femoris (outside).Muscle elasticity analysis showed increased changes except for the rectus femoris (right foot) and gastrocnemius (both feet). Muscle recovery time analysis showed vastus lateralis (both feet), rectus femoris (right foot), and biceps femoris (outside foot). Except for this, there was reduced change. Conclusions Through the combined application of stretching, muscle tension, muscle stiffness, and muscle elasticity showed overall increased changes. Muscle recovery time showed an overall decrease.

배경: 근막이완기법과 수동적 스트레칭을 병행한 실험이 직장여성의 하지체형에 미치는 연구는 보고되지 않았 다. 목적: 고정자세로 근무하는 직장여성에게 근막이완기법과 수동적 스트레칭을 적용하여 체성분분석(세포내액, 골 격 근량, 체세포량)에 어떤 변화를 미치는지를 연구하는 것이었다. 방법: 실험군과 대조군을 각각 15명씩 구성하여 실 험 군에게는 주 2회, 총 9주간 18회 하체 집중 근막이완기법과 수동적 스트레칭을 시행하고, 대조군은 능동적 스트레 칭 설명서를 보고 스스로 주 2회 이상 스트레칭을 하도록 했다. 수집한 자료는 분산분석으로 분석하였다. 결과: 실험집 단의 체성분 중 세포내액(p < .05), 골격 근량(p < .048), 체세포량 (p < .047)이 유의하게 증가하였다. 결론: 직장여성의 하지 부종이 감소하였으며, 기초자료로서 가치가있다 본다.

Background: There have been no reports of studies on the effect of a combination of myofascial relaxation technique and passive stretching on the lower extremity body shape of working women. Purpose: This study aimed to examine the effects of myofascial relaxation technique and passive stretching on body composition and body composition analysis (intracellular fluid, skeletal muscle mass, body cell mass), etc. Methods: The subjects of this study were 30 women at a body shape management center who had many problems with their subjective lower extremity body shape. Fifteen subjects were in the experimental group and the control group. The experimental group applied the fascial relaxation technique twice a week for nine weeks. The control group conducted stretches by themselves at least twice a week according to the active stretching instructions. The ANOVA program analyzed the data. Results: In the experimental group, intracellular fluid (p < .05), skeletal muscle mass (p < .048), and body cell mass (p < .047) were significantly increased. Conclusion: The lower extremity edema of working women decreased

This study aimd to determine the effect of proprioceptive neuromuscular facilitation (PNF) iliopsoas muscle stretching techniques on the pain and hip joint range of motion in patients with low back pain. In this study, PNF iliopsoas muscle stretching techniques was applied to three patients with low back pain. PNF iliopsoas muscle stretching techniques was performed 13 times during intervention phase. The subjects were measured 5 times in the baseline phase, 13 times in the intervention phase. A visual analogue scale (VAS) was used for the measurement of the level of pain. The FABER test (FABERT), modified Thomas test (MTT), and prone hip extension test (PHET) were used for the measurement of the hip joint range of motion. The pain was reduced compared in the patients to those of pre-tests, and the hip joint range of motion was improved compared to the range of pre-tests. The study results verified that PNF iliopsoas muscle stretching techniques are useful when applied to patients with low back pain.

[목적] 본 연구는 골퍼들에게 흔히 발생하는 족저근막염에 대해, 근거 기반의 예방 및 관리 운동 프로그램을 종합적 으로 제시하는 데 목적이 있었다. [방법] 선행 연구와 임상 지침을 바탕으로 족저근막염의 병태생리학적 특성, 골프 와의 연관성, 위험 요인을 검토하였으며, 스트레칭, 근력 강화, 균형 훈련으로 구성된 예방 중심의 운동 프로그램에 대해 문헌을 고찰하였다. [결과] 족저근막염의 예방 및 관리를 위해서는 족저근막 특이적 스트레칭과 종아리 근육 스 트레칭을 통한 유연성 향상, Short Foot Exercise를 포함한 발 내재근 강화 및 하퇴부 근력 강화, 그리고 균형 및 고 유수용성 훈련이 효과적인 것으로 나타났다. [결론] 골퍼의 족저근막염은 스트레칭, 근력 강화, 균형 훈련을 포함한 포괄적 예방 프로그램을 통해 효과적으로 관리할 수 있으며, 본 연구에서 제시된 근거 기반 지침은 골퍼의 족저근막 염 예방과 건강한 골프 활동 지속에 기여할 수 있을 것으로 기대된다.

[Purpose] This study aimed to comprehensively present evidence-based exercise programs for plantar fasciitis prevention and management in golfers. [Methods] Based on previous research and clinical guidelines, the pathophysiological characteristics, golf-related associations, and risk factors of plantar fasciitis were reviewed, and literature on prevention-focused exercise programs consisting of stretching, strength training, and balance training was examined. [Results] For plantar fasciitis prevention and management, plantar fascia-specific stretching and calf muscle stretching for flexibility improvement, intrinsic foot muscle strengthening including Short Foot Exercise and lower leg strength training, and balance and proprioceptive training were found to be effective. [Conclusion] Plantar fasciitis in golfers can be effectively managed through comprehensive prevention programs including stretching, strength training, and balance training, and the evidence-based guidelines presented in this study are expected to contribute to the prevention of plantar fasciitis in golfers and the maintenance of healthy golf activities.

[목적] 본 연구의 목적은 일반인 남성을 대상으로 냉 침수요법이 근 피로 회복 및 혈중 피로 지표에 미치는 영향을 조사하는 것이다. [방법] 무작위 교차설계(randomized cross-over)를 통해 22명의 참가자를 통제 그룹(control group, CG), 냉 침수요법 그룹(cold-water immersion group, CIG), 스트레칭 그룹(stretching group, SG) 총 세 그룹으로 나누었다. 근 피로를 유발하기 위해 리스트 롤러(wrist roller) 운동을 수행하였고, 각 그룹별 처치는 10분간 진행하였다. 피로 유발 후 처치 방법에 따른 근 피로 회복 및 혈중 피로 지표를 확인하기 위해 근력, 근지구력, 손목 관절가동범위, 통증 척도와 크레아틴 키나아제, 젖산탈수소효소, 미오글로빈, C-반응성 단백질을 확인하였다. [결과] 근력, 근지구력, 손목 관절가동범위, 통증 척도는 대부분 측정 시점에서 CG, SG보다 CIG가 유의하게 회복되었다. 혈중 피로 지표인 크레아틴 키나아제는 24시간 후에, 젖산탈수소효소, 미오글로빈, C-반응성 단백질은 회복 처치 직후부터 CIG가 CG, SG에 비해 유의하게 회복된 것으로 나타났다. [결론] 본 연구 결과 냉 침수요법이 스트레칭보다 근 피로 회복 및 혈중 피로 지표에 긍정적인 영향을 미친다는 것을 확인하였다.

[Purpose] The purpose of this study is to investigate the effects of cold-water immersion on muscle fatigue and blood fatigue markers in healthy male individuals. [Method] A randomized cross-over design was used, dividing 22 participants into three groups: the control group (CG), cold-water immersion group (CIG), and stretching group (SG). Wrist roller exercise was performed to induce muscle fatigue, and each group was treated for 10 minutes. To determine muscle fatigue recovery and blood fatigue markers according to the treatment method after fatigue induction, we analyzed muscle strength, muscle endurance, wrist joint range of motion, pain scale, and blood fatigue markers, including creatine kinase (CK), lactate dehydrogenase (LDH), myoglobin (Mb), and C-reactive protein (CRP). [Result] Muscle strength, muscle endurance, wrist range of motion, and pain scale showed significantly greater recovery in the CIG compared to the CG and SG at most measurement time points. Among the blood fatigue markers, CK showed significant recovery in the CIG 24 hours after treatment, while LDH, Mb, and CRP exhibited significant recovery immediately after the recovery intervention compared to the CG and SG. [Conclusion] The results of this study confirm that cold-water immersion has a positive effect on muscle fatigue recovery and blood fatigue markers.

[목적] 본 연구는 대학골프 선수들의 운동량이 증가함에 따라 나타나는 피로, 부상 등을 관리하고 경기력의 향상 및 유지를 위한 방법으로, 골프 특성에 맞는 효과적인 회복운동을 제시하기 위해 실시되었다. [방법] 본 연구의 목적을 달성하기 위해 골프선수 8명을 대상으로 무처치, 걷기, 스트레칭, 폼 롤러 회복운동을 구분하고 교차 적용하여 체간 회전 가동범위, 반동 동작 점프(CMJ), 드라이버 수행력, 라운딩 스코어를 측정하였으며, 회복운동 방법 간의 차이를 알아보기 위해 Kruskal-Wallis test를 실시하였다. [결과] 본 연구의 결과를 살펴보면, 드라이버 수행력에서 폼 롤링 회복운동이 무처치 집단에 비해 클럽헤드스피드(p<.05), 볼 스피드(p<.05), 볼 비행거리(p<.01), 총 비거리(p<.05)에서 통계 적으로 유의하게 증가한 것으로 나타났으며, 스트레칭 적용 시에도 볼 비행거리(p<.05)에서 통계적으로 유의한 결과가 나타났다. 체간 회전가동범위와 반동동작점프, 라운딩 스코어에는 회복운동에 따른 유의한 차이가 나타나지 않았다. [결론] 골프 선수들의 경기력 향상을 위한 방법으로 폼 롤러를 활용한 회복운동이 효과적이라 판단되며, 추후에는 수준별, 성별, 연령 등을 고려하여 중장기적 효과에 대한 검증과 부상예방 효과에 대한 연구가 필요할 것이다.

[Purpose] This study was conducted to suggest an effective recovery method for improving the performance of college golf players. [Method] In order to achieve the purpose of this study, 8 college golf players were recruited and divided into Walking, Stretching, Foam roller recovery exercises and control group, the study design was crossover type. Trunk rotation range of motion, muscle power and fatigue (CMJ), driver performance, and rounding score were measured. Kruskal-Wallis test was performed to determine the difference between the recovery exercise methods. [Result] As a result of this study, driver performance, the foam rolling recovery exercise showed statistically significant increase in club head speed (p<.05), ball speed (p<.05), carry (p<.01), and total distance (p<.05) compared with control group, for stretching was applied, statistically significant results were found in the carry (p<.05) compared with control group. There was no significant difference according to the recovery exercise in the trunk rotation range, CMJ, and rounding score. [Conclusion] Recovery exercise using foam rollers is considered to be effective as a method for improving golf players' performance. In the future, it is necessary to verify the mid- to long-term effects and study the effects of injury prevention in consideration of level, gender, and age.

본 연구의 목적은 호흡기 장애가 있는 제한성 폐질환 노인의 체간에 관절가동술과 스트레칭이 호흡기능, 자 세, 신체피로감의 개선효과를 확인하는데 있다. 연구대상자는 총 10명으로 2014년 1월부터 동년 11월까지 8주간 비 동시적으로 진행되었고, 주 3회, 1일 30분간 체간에 관절가동술과 스트레칭을 실시하였다. 연구 결과 FVC, FEV1, 체 간자세, 체간움직임, 신체피로감이 유의하게 개선되었다(p<.05). 본 연구를 통해 관절가동술과 스트레칭이 호흡기장애 노인의 호흡기능, 체간자세, 체간움직임, 신체피로감을 동시에 개선시킬 수 있는 호흡정형물리치료가 될 수 있음을 확인하였다. 이후 연구들에서는 제한성 폐질환 노인을 대상으로 본 연구에서 적용한 호흡정형물리치료와 운동 분야 들과의 치료적 융복합을 통한 지속적인 연구가 필요하겠다.

The purpose of this study was to examine the effects of trunk mobilization and stretching activities on respiratory function, trunk posture, and physical fatigue for elderlies with restrictive lung diseases and related respiratory impairment. The present study was conducted with ten subjects, participating for eight weeks between January and November 2014. Subjects performed trunk mobilization and stretching routines for 30 minutes per day for three days each week. The study results showed that there were significant improvements in FVC and FEV1, trunk posture, trunk movement and physical fatigue(p<.05). The study results verified that trunk mobilization and stretching activities can be used as respiratory orthopedic manual therapy to improve respiratory function, trunk posture, trunk movement and physical fatigue simultaneously for elderly with respiratory impairment. Continuous studies through therapeutic convergence with the exercise field along with the respiratory orthopedic manual therapy that used in this study for elderly people with restrictive lung diseases will be necessary for the future.

Purpose : The purpose of this study was to compare the effects of modality and exercise therapy on delayed onset muscle soreness. Method: Subjects were assigned to 18 male and female(ultrasound group: 6 , stretching : 6, control group : 6) at random. Ultrasound was treated insertion of quadriceps frequency: 1MHz, Strength: 1.5 / ㎠, Time: 10 minutes. Stretching, active stretching, was repeated total 10 times and 30 seconds in duration on hip flexion which is opposite effect of quadriceps and knee flexion in a prone position. All of data calculated average and standard deviation and analyzed to investigate the effects within ultrasound therapy and stretching group using repeat measured ANOVA, one-way ANOVA and LSD. Result : Ultrasound and stretching group was not represented to statistically significant difference between groups. Conclusion : Ultrasound group showed that the effects on MMT, PPT, ROM, VAS in differences in group by time interaction but ultrasound and stretching group was not represented to statistically significant difference between groups.

The purpose of this study was to identify differences of proprioception and muscle strength in five years over chronic hyperextension stretching event in female athletes. Twenty-eight Female university students(Control, n＝7; Gymnastics, n＝7; Taekwondo, n＝7; Ballet, n＝7) were assigned to 1 of 4 groups. Subjects were excluded if they had a lower extremity injury, vestibular problems, visual problems or concussion in the 12 weeks before the study. Experimental data were analyzed statistically by one-way ANOVA using Window SPSS/PC program. And then, LSD was used as post hoc test. A significant level was considered as p<.05. The results are as follows; 1.There were significant differences in muscle function among groups. 1)There were significant differences in left knee extensor strength at 60°/sec among groups(p<.05) 2)There were significant differences in right and left knee extensor strength at 180°/sec among groups(p<.05) 3)There were significant differences in left knee flexor strength at 180°/sec among groups(p<.05) 2.There were no significant differences in proprioception among groups. In conclusion, muscle function among Gymnastic, Taekwondo, Ballet and Control group were significantly different, but differences of proprioception were not significant among groups.

The purpose of the study was investigate the effect of cool-down and warm-up on Delayed Onset Muscle Soreness(DOMS). 20 healthy male and female student were participated in the study. They were randomly assigned to 4 groups; 1) a control group{n = 5), 2) warm-up group(n = 5) , 3) cool-down group{n = 5), 4) combined group that received warm-up and cool-down. To induce the DOMS at elbow flexor groups of non-dominant arm, they performed eccentric contraction exercises by isokinetic machine(KIN-KOM). The girth of upper arm was measured at the just before, just after exercise, after 24 hr, after 48 hr, after 72 hr, after 96 hr. At the highest point of upper arm, the girth was measured by a tapeline. Muscle soreness level was evaluated at same as above intervals by visual analog scale(VAS). There were significant difference of VAS between groups{P< 0.05). There were no significant difference of upper arm girth between group(P> 0.05). There were no effect of warm-up and cool-down exercise on DOMS and girth.

Background Jack-knife stretching is a newly developed static hamstring stretching exercise. However, no studies have compared this stretching exercise to hamstring stretching with proprioceptive neuromuscular facilitation (PNF). Purpose This study compared the effects of PNF hamstring stretching and jack-knife stretching on hamstring flexibility. Study design Randomized controlled clinical trial Methods Twenty-four adults with bilateral hamstring tightness were randomly assigned to the PNF hamstring stretching or jack-knife stretching group. All participants performed PNF hamstring stretching or jack-knife stretching for 150 s. Before and after hamstring stretching, the participants completed the active knee extension (AKE), active straight leg raise (ASLR), and finger-to-floor distance (FFD) tests. Lumbar flexion and the anterior pelvic tilt angle were measured during the FFD test. Results Both hamstring stretching exercises increased the knee extension angle during the AKE test, hip flexion angle during the ASLR test, and lumbar flexion and anterior pelvic tilt angle during the FFD test while decreasing the FFD value (p<0.05). However, no significant between-group differences were found (p>0.05). Conclusions PNF hamstring stretching and jack-knife stretching have similar beneficial effects on hamstring flexibility.