Dissertations / Theses on the topic 'Closed kinetic chain exercises'

Thesis (M.S.E.S.)--University of Toledo, 2008.<br>Typescript. "Submitted as partial fulfillments of the requirements for the Masters of Science Degree in Exercise Science." "A thesis entitled"--at head of title. Bibliography leaves 31-33.

Musculoskeletal injuries are commonly associated with muscle atrophy as a function of immobilization or change of normal function. For example, injuries to the anterior cruciate ligament (ACL) which may involve ligament reconstruction, results in the "quadriceps avoidance" gait which leads to atrophy of the knee extensormuscles. In these situations it is not clear whether or not the atrophy is associated with loss of specific muscle fibre types with accompanying functional deficits. Such knowledge would be helpful in implementing exercise regimes designed to compensate for loss of particular fibre types. It is believed that isokinetic exercise performed at speeds below 180° per second strengthens type I muscle fibres, and type II fibres at fast speeds. However, there is no evidence to indicate the specific muscle fibre response to different rates of muscle contraction. Identification of muscle fibre type is most directly determined by biopsy technique but is too invasive for a routine measurement. Electromyography median frequency has been used as a non-invasive measure to infer muscle fibre composition in various studies. However, the reliability and accuracy of this technique has been questioned and improvement is necessary. This research was designed to provide a more accurate and reliable protocol for the determination of EMG median frequency which may be used, after validation against more direct biopsy techniques, as a routine method for inferring muscle fibre composition. The investigation also explored the muscular response as measured by EMG median frequency to varying speeds of muscle contraction, fatiguing exercise and atrophy following ACL reconstruction. The ultimate aim of this research was to improve the reliability of the determination of EMG median frequency to enhance its application as a predictor of muscle fibre composition. This provides information which may improve ACL rehabilitation programs designed to restore and prevent specific muscle fibre types loss that have not previously been targeted by current rehabilitation programs. This research was conducted in three studies. Study one determined the stability of the EMG median frequency bilaterally for the quadriceps and hamstrings muscles and identified the mode of contraction associated with the greatest reliability. The strength and EMG median frequency of the vastus lateralis, medial hamstrings and vastus medialis of 55 subjects was determined across 5 speeds from 0° to 240° per second using a Kin-Com isokinetic dynamometer and an EMG data acquisition system. Isometric contraction was found to have the least bilateral discrepancy (4.01% ±3.06) and between trials standard deviation (4.50) in the vastus lateralis, medial hamstrings and vastus medialis. Study two investigated the EMG median frequency changes in the vastus lateralis which occur immediately following different speeds of isokinetic exercise to the point of fatigue in normal subjects. Thirty-four subjects participated in the study, and performed a 90-second period of isokinetic exercise to activate the knee extensors at either 30° or 300° per second. EMG median frequency of the vastus lateralis was determined before, immediately after and 7 minutes after the fatiguing exercise. The percentage drop in EMG median frequency of the vastus medialis was gnificantly (p<0.05) greater after slow speed (27.9%) than fast speed (20.25%) exercise, while no significant difference was found for the percentage drop in extension torque. Full recovery was found 7 minutes after the fatiguing exercise. By reference to previous research showing a relationship between EMG median frequency and muscle fibre type, an increase in activation of type I muscle fibres with slow speed exercise and an increase in type II muscle fibres with fast speed exercise was observed. Study three identified the changes in EMG median frequency following ACL reconstruction and evaluated the bilateral differences in EMG median frequency of the knee muscles. The relationships between EMG median frequency and the measures of knee functional ability, knee muscle strength, age and time since surgery were also investigated. Twelve subjects who had undergone ACL reconstruction using a semitendinosus and gracilis graft 6 to 12 months earlier, participated in the study. EMG median frequency was determined from an 8-second isometric contraction and knee functional ability was assessed using the Cincinnati Rating Scale. Bilateral EMG median frequency shifts were inconsistent among subjects. On the basis of previous research which indicated a relationship between EMG median frequency and fibre type, no consistent pattern of muscular fibre type atrophy subsequent to ACL reconstruction occurred within 6 to 12 months (ranged from -43 to 57 Hz). Additionally, no significant correlations were found between the EMG median frequency and the knee functional score and knee extension and flexion torques, age, time since operation and the bilateral differences in EMG median frequency. The results of this investigation will serve to improve the reliability of EMG median frequency across a range of conditions in which it has been evaluated. Further research is needed to confirm the relationship between EMG median frequency and direct observations of muscle fibre composition to improve the predictive value of this measure. Following this validation it will be possible to evaluate the bilateral EMG median frequency shift to infer the type of muscle fibre atrophy, and use this measure in determining the efficacy of specific rehabilitation programs. In conclusion * An 8-second isometric contraction is recommended for determining EMG median frequency. * EMG median frequency of a muscle decreases significantly more after slow fatiguing exercise than after fast speed fatiguing exercise. * There was no generalised bilateral EMG median frequency shift found in a group of subjects 6 to 12 months following semitendinosus and gracilis graft ACL reconstruction. * The results of this study will serve to improve the reliability of procedures used to determine EMG median frequency under a range of different contractile conditions. The EMG median frequency changes in response to these conditions require further validations with muscle biopsy in future.

Musculoskeletal injuries are commonly associated with muscle atrophy as a function of immobilization or change of normal function. For example, injuries to the anterior cruciate ligament (ACL) which may involve ligament reconstruction, results in the "quadriceps avoidance" gait which leads to atrophy of the knee extensormuscles. In these situations it is not clear whether or not the atrophy is associated with loss of specific muscle fibre types with accompanying functional deficits. Such knowledge would be helpful in implementing exercise regimes designed to compensate for loss of particular fibre types. It is believed that isokinetic exercise performed at speeds below 180° per second strengthens type I muscle fibres, and type II fibres at fast speeds. However, there is no evidence to indicate the specific muscle fibre response to different rates of muscle contraction. Identification of muscle fibre type is most directly determined by biopsy technique but is too invasive for a routine measurement. Electromyography median frequency has been used as a non-invasive measure to infer muscle fibre composition in various studies. However, the reliability and accuracy of this technique has been questioned and improvement is necessary. This research was designed to provide a more accurate and reliable protocol for the determination of EMG median frequency which may be used, after validation against more direct biopsy techniques, as a routine method for inferring muscle fibre composition. The investigation also explored the muscular response as measured by EMG median frequency to varying speeds of muscle contraction, fatiguing exercise and atrophy following ACL reconstruction. The ultimate aim of this research was to improve the reliability of the determination of EMG median frequency to enhance its application as a predictor of muscle fibre composition. This provides information which may improve ACL rehabilitation programs designed to restore and prevent specific muscle fibre types loss that have not previously been targeted by current rehabilitation programs. This research was conducted in three studies. Study one determined the stability of the EMG median frequency bilaterally for the quadriceps and hamstrings muscles and identified the mode of contraction associated with the greatest reliability. The strength and EMG median frequency of the vastus lateralis, medial hamstrings and vastus medialis of 55 subjects was determined across 5 speeds from 0° to 240° per second using a Kin-Com isokinetic dynamometer and an EMG data acquisition system. Isometric contraction was found to have the least bilateral discrepancy (4.01% ±3.06) and between trials standard deviation (4.50) in the vastus lateralis, medial hamstrings and vastus medialis. Study two investigated the EMG median frequency changes in the vastus lateralis which occur immediately following different speeds of isokinetic exercise to the point of fatigue in normal subjects. Thirty-four subjects participated in the study, and performed a 90-second period of isokinetic exercise to activate the knee extensors at either 30° or 300° per second. EMG median frequency of the vastus lateralis was determined before, immediately after and 7 minutes after the fatiguing exercise. The percentage drop in EMG median frequency of the vastus medialis was gnificantly (p<0.05) greater after slow speed (27.9%) than fast speed (20.25%) exercise, while no significant difference was found for the percentage drop in extension torque. Full recovery was found 7 minutes after the fatiguing exercise. By reference to previous research showing a relationship between EMG median frequency and muscle fibre type, an increase in activation of type I muscle fibres with slow speed exercise and an increase in type II muscle fibres with fast speed exercise was observed. Study three identified the changes in EMG median frequency following ACL reconstruction and evaluated the bilateral differences in EMG median frequency of the knee muscles. The relationships between EMG median frequency and the measures of knee functional ability, knee muscle strength, age and time since surgery were also investigated. Twelve subjects who had undergone ACL reconstruction using a semitendinosus and gracilis graft 6 to 12 months earlier, participated in the study. EMG median frequency was determined from an 8-second isometric contraction and knee functional ability was assessed using the Cincinnati Rating Scale. Bilateral EMG median frequency shifts were inconsistent among subjects. On the basis of previous research which indicated a relationship between EMG median frequency and fibre type, no consistent pattern of muscular fibre type atrophy subsequent to ACL reconstruction occurred within 6 to 12 months (ranged from -43 to 57 Hz). Additionally, no significant correlations were found between the EMG median frequency and the knee functional score and knee extension and flexion torques, age, time since operation and the bilateral differences in EMG median frequency. The results of this investigation will serve to improve the reliability of EMG median frequency across a range of conditions in which it has been evaluated. Further research is needed to confirm the relationship between EMG median frequency and direct observations of muscle fibre composition to improve the predictive value of this measure. Following this validation it will be possible to evaluate the bilateral EMG median frequency shift to infer the type of muscle fibre atrophy, and use this measure in determining the efficacy of specific rehabilitation programs. In conclusion * An 8-second isometric contraction is recommended for determining EMG median frequency. * EMG median frequency of a muscle decreases significantly more after slow fatiguing exercise than after fast speed fatiguing exercise. * There was no generalised bilateral EMG median frequency shift found in a group of subjects 6 to 12 months following semitendinosus and gracilis graft ACL reconstruction. * The results of this study will serve to improve the reliability of procedures used to determine EMG median frequency under a range of different contractile conditions. The EMG median frequency changes in response to these conditions require further validations with muscle biopsy in future.

Neuromuscular control is believed to play an essential role during dynamic knee joint stabilisation. Evaluation of voluntary muscle action can be delineated as support strategies against external loading moments (Lloyd & Buchanan, 2001). The aim of this study was to determine if males and females exhibit differences in knee muscle action and cocontraction during voluntary isometric closed kinetic chain force generation in various directions in the horizontal plane representative of applied loads transverse to the long axis of the shank. Twenty-six healthy young adults (13 male, 13 female) stood with their dominant leg in a boot fixed to a force platform. A force target matching protocol required subjects to position a cursor (projected on a video screen) over a target and maintain the position for one second. To control the cursor, loads were applied against the force platform with their dominant leg to produce various combinations of anterior-posterior, medial-lateral loads while maintaining constant inferior-superior loads. A successful target match required a normalised force magnitude of equal effort for each subject and target location which triggered the recording of electromyography (EMG) for eight muscles crossing the knee joint. EMG was normalised to percent maximum voluntary isometric contraction. A mean magnitude of muscle activation, mean direction of muscle activation and a muscle specificity index was determined using EMG vectors. In addition, cocontraction indices were also computed for antagonist muscle pairs. Based on similar previous research, it was hypothesised that females would have greater quadriceps and hamstrings coactivation, greater muscle activation magnitudes, lower specificity for the quadriceps than males and no difference in hamstring characteristics. In our study, females significantly cocontracted their vastus lateralis and lateral gastrocnemius muscles to a greater degree than males (p=0.001). No significant differences were observed across sexes for the cocontraction of quadriceps and hamstrings or the lateral quadriceps and gastrocnemius muscles. Females displayed significantly lower specificity than males in their semitendinosus (p=0.025) and tensor fascia lata (p=0.012) activity patterns, greater magnitude of muscle activation in their lateral gastrocnemius (p=0.002) and tensor fascia lata (p<0.003) and no statistical difference in the other muscles. Furthermore, the activation patterns in our study grossly differed from previous open kinetic chain force target matching. These findings indicate that healthy young males and females have differences in their knee muscle control strategies and that knee muscle recruitment patterns differ during weight bearing and non-weight bearing tasks.

Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciada em Fisioterapia<br>Introdução: Existem diversos tipos de alongamento. Estes podem ser realizados em cadeia cinética aberta (CCA) e cadeia cinética fechada (CCF). No entanto, não se conhecem estudos que tenham explorado essas diferenças. Objetivo: Avaliar a diferença da amplitude articular, num momento agudo, entre o alongamento realizado em CCA e CCF. Metodologia: Os testes usados para medição da flexibilidade da musculatura dos isquiotibiais neste estudo foram o: Back Saver Seat and Reach (BSSR); 90/90 Straight Leg Raising Test (90/90 SLR) e os testes de flexão e de extensão da coxa femoral. Os dados dos três últimos testes referidos foram inseridos no programa Kinovea para avaliação da amplitude articular. Resultados: após a análise dos dados obtidos, verificou-se que não existem diferenças estatisticamente significativas relativamente ao BSSR, 90/90 SLR, e teste de flexão e extensão da coxo-femoral com os dois tipos de alongamento realizados. No entanto, ambos os alongamentos produzem aumento da amplitude articular. Conclusão: não existem diferenças significativas na amplitude articular entre a realização do alongamento dos isquiotibiais realizado em CCA e CCF.<br>Introduction: There are several types of stretching. These can be performed on open kinetic chain (CCA) and closed kinetic chain (CCF). However, there are no known studies that have explored these differences. Objective: To evaluate the difference in articular amplitude, at an acute moment, between the streching performed in CCA and CCF. Methodology: The tests used to measure the flexibility of the hamstring muscles in this study were: Back Saver Sit and Reach Test (BSSR); the 90/90 Straight Leg Raising Test (90/90 SLR) and the hip flexion and extension tests. Data from the last three mentioned tests were inserted into the Kinovea program for joint amplitude evaluation. Results: After analyzing the obtained data, it was verified that there are no statistically significant differences in the BSSR, 90/90 SLR and the hip flexion and extension test for the two types of stretching performed. However, both elongations produce increased joint amplitude. Conclusion: there are no significant differences in the joint amplitude between the performance of the hamstring elongation performed in ACC and CCF.<br>N/A

Darbo tikslas – įvertinti nugaros giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus atviroje kinetinėje grandinėje. Pasirinktam darbo tikslui įgyvendinti buvo iškelti šie uždaviniai: 1. Įvertinti nugaros giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus atviroje kinetinėje grandinėje ant stabilios atramos. 2. Įvertinti nugaros giliųjų ir paviršinių raumenų elektrinį aktyvumą atliekant pratimus atviroje kinetinėje grandinėje ant nestabilios atramos. 3. Palyginti giliųjų raumenų elektrinį aktyvumą su paviršinių raumenų elektriniu aktyvumu kiekvieno pratimo metu. 4. Palyginti raumenų elektrinį aktyvumą tarp identiškų pratimų, atliekamų ant stabilios atramos, su atliekamais ant nestabilios atramos. 5. Palyginti raumenų elektrinį aktyvumą tarp identiškų pratimų, kurių atlikimas skiriasi judesyje dalyvaujančių apatinių galūnių skaičiumi. Tyrime dalyvavo 20 darbingo amžiaus vyrų, per tris mėnesius neturėjusių nusiskundimų dėl nugaros apatinės dalies skausmo. Tyrimą sudarė dvi dalys: 15 minučių trukmės tiriamųjų apšilimas (5 minutės veloergometro mynimui ir 10 minučių tempimo pratimams) ir tiriamųjų testavimas. Tiriamųjų testavimą sudarė 11 pratimų ir 2 testavimo padėtys maksimaliam valingam testuojamų raumenų susitraukimui išgauti. Išvados: 1. Dauginio raumens elektrinis aktyvumas buvo didesnis nuo 19,5 % iki 27,8 % nei tiesiamojo nugaros raumens krūtininės dalies elektrinis aktyvumas penkiuose iš septynių pratimų, atliekamų ant stabilios... [toliau žr. visą tekstą]<br>The purpose of this research: To evaluate electric activity of deep and superficial back muscles during open kinetic chain exercises. Goals of this research: 1. To evaluate electric activity of deep and superficial back muscles during open kinetic chain exercises performed on stable support. 2. To evaluate electric activity of deep and superficial back muscles during open kinetic chain exercises performed on labile support. 3. To compare electric activity of deep and superficial back muscles during each exercise. 4. To compare electric activity of back muscles between the same exercise pairs performed on different support type. 5. To compare electric activity of back muscles during exercise performed with one lower limb with exercise performed with both lower limbs. During this research 20 men, who had no recent complaints about low back pain (>3 months), were tested. The testing consisted of two parts: 15 min. for warm up exercises (5 min. – cardio respiratory warm up and 10 min. – stretching exercises) and the main testing. The main testing consisted of 11 exercises and 2 exercise to determine maximum voluntary contraction. Conclusion: 1. Electric activity of multifidus muscle was statistically significant higher than electric activity of thoracic part of erector spinae muscle during 5 from 7 exercises performed on stable support (p<0,05). 2. Electric activity of multifidus muscle was statistically significant higher than electric activity of thoracic part of erector spinae... [to full text]

碩士<br>國立成功大學<br>工程科學系碩博士班<br>94<br>Since having a pair of strong arms is essential for human beings, the training of our upper extremities has become an important issue. Different types of open kinetic chain exercises, such as bench-press, are popular exercises used in strengthening the upper extremity. In the literature review, the investigations in the biomechanics of the open kinetic chain exercises of the lower extremity have greatly been discussed, while the research regarding the biomechanics of the open kinetic chain exercises of the upper extremity is less. This study aims to establish a biomechanical experimental model for the open kinetic chain exercises of the upper extremity through the Motion Analysis System. Ten subjects, volunteered for this survey, were asked to perform two sets of closed kinetic chain exercise and open kinetic chain exercises for investigating the differences. The kinetics and kinematics of the upper extremity were calculated and analyzed. The joint loading were significantly different among the two sets of exercises. During closed kinetic chain exercises and open kinetic chain exercises, push-up has smaller joint loading comparing to bench-press. Additionally, push-up wrist of anterior/posterior, elbow of medial/lateral and shoulder anterior/posterior can reduce the shearing forces on the upper extremity. In this study, we have established a biomechanical experimental model for the closed kinetic chain exercises and open kinetic chain exercises of the upper extremity. The data provided in this study maybe helpful in strengthening and rehabilitation of the upper extremity.

碩士<br>國立臺灣體育大學(桃園)<br>運動保健科學研究所<br>96<br>Purpose: The purpose of this study was to investigate the effect of fatigue induced by push-up and bench-press exercises on proprioception under open kinetic chain and closed kinetic chain test mode. Methods: Twenty health males ( age 22.9 ± 2.49 years ) with no histories of upper extremity injuries volunteered for this study. Subjects performed repeated push-up or bench- press at the rhythm of one for every 2 seconds. When they can’t catch up with the rhythm then proceeded with the final three more to the point of muscular fatigue. The proprioception before and after fatigue were assessed by electrogoniometers. The recording of the absolute angular error of active reproduction was set at 30° of shoulder horizontal abduction and 45° of elbow flexion. The proprioception before and after fatigue was analyzed with a paired t-test. And the effect of fatigue and test mode was analyzed with a two-way ANOVA. Results: Paired t-test revealed a significant difference between the pre and post fatigue values induced by bench-press for shoulder and elbow mean absolute angular error under open kinetic chain and closed kinetic chain test mode (p＜0.05 ). There was also significant difference between the pre and post fatigue values induced by push-up for shoulder and elbow mean absolute angular error under open kinetic chain and closed kinetic chain test (p＜0.05 ). No significant difference between the pre and post fatigue values for shoulder and elbow mean absolute angular error under 2 test mode (p＜0.05 ). Conclusion: muscle fatigue induced by both bench-press and push-up, had a negative effect on the shoulder and elbow proprioception. And no significant difference between fatigue induced by bench- press and push-up for shoulder and elbow proprioception under 2 test mode.

碩士<br>國立臺灣體育運動大學<br>運動健康科學系碩士班<br>105<br>Purpose: The investigation was to research the effect of twelve week lower extremities closed kinetic chain exercise for risk factors of elders’ falling. Method: Recruited 30 elders whose ages were above 65, including 27 females and 3 males. Before and after intervention, we evaluated their physical fitnesses and general health conditions, including blood pressure, weight, Body Mass Index (BMI), waist circumference, hip circumference, muscle strengths of lower extremities and balance. The collected data were analyzed by one-way ANOVA, Descriptive Statistics and independent t-test. Results: The hip rang of motion, chair sit and reach test, 10 meter walk, 30 second sit to stand test improved after twelve week of the intervention. These tests were statistically significant (p＜.05). In two-minute step test, 6 meter-up-and-Go, backscratch test, 6-min walk test and Berg balance tests were no significant differences. Also, there was no statistically significant relationship between systolic pressure, diastolic pressure, BMI, waist circumference, and hip circumference. Conclusion: After 12-week of intervention, the ambulation ability, flexibility and lower extremities muscle strength were better than control group. Also, there was a statistical difference between two groups (p<.05). It demonstrates that the intervention is effective. Moreover, long-term and regulatory exercise can decline the risk of elders falling. It also can be the instruction for elders exercise in the future.

碩士<br>長庚大學<br>工業設計學系<br>100<br>This study applied the concept of closed chain exercise to WaterBall, which combines rehabilitation exercises with a digital game. By using WaterBall, the elderly can enjoy the benefits of both entertainment and rehabilitation. In addition, WaterBall provides multi-touch control, is easy to use, and have the potential to improve physical activity in older adults The elderly can play the game intuitively. WaterBall Exergaming was used by 52 residents of an elderly community, and they reported that WaterBall offers exercise and fitness, enhances the efficiency of exercises, and provides entertainment and interaction.

碩士<br>國立成功大學<br>物理治療研究所<br>95<br>Previous studies on shoulder muscle strengthening and rehabilitation emphasized the use of open kinetic chain exercises. However, there is limited information on closed kinetic chain exercises. The purpose of this study was to analyze and compare kinetics and electromyographic (EMG) data during closed kinetic chain exercises, in order to explore the kinetic characteristic and EMG data of the shoulder weight-bearing exercise. Twenty male subjects participated in the study. They performed different shoulder weight-bearing exercises by controlling several factors, including foam, posture, support, and position. Each subject performed exercises directly bearing on the force plate or foam, in hand-sand-knees or hands-and-feet postures combined four point, three point, diagonal, or unilateral support. Then each subject was asked to shift his body forward, backward, leftward, and rightward to different positions. Outcome measures were the angle of the shoulder joint, EMG activities of shoulder muscles, shoulder joint reaction force, and torque. In our study, the foam cause a significant increase of shoulder joint reaction force in anterior and lateral direction but decrease in inferior direction (p value < 0.05), and didn’t have influence for shoulder torque (p value > 0.05). The foam resulted in the EMG slightly increased, but there was on significant difference (p value > 0.05). For all outcome measures, the hands-and-feet posture was significant higher than the hands-and-knees posture (p value < 0.05). The diagonal support resulted in the highest shoulder joint reaction force in anterior and lateral direction, and the three point support resulted in the highest shoulder joint reaction force in inferior direction (p value < 0.05). The shoulder flexor and scapular upward rotator had the highest EMG firing in the diagonal support (p value < 0.05), but other shoulder muscles had the highest EMG firing in the unilateral support (p value < 0.05). However, the hands-and-feet posture could enhance the difference between different supporting methods. The extension and horizontal adduction positions could in highest EMG activities and shoulder reaction force in inferior direction. The posture and support were the primary factors to influence the shoulder joint reaction force, torque, and EMG activities. The hands-and-feet posture combined diagonal support or unilateral for different muscles resulted in the highest muscle loading, and shoulder loading. The information about muscle activities and kinetic data during shoulder weight-bearing exercises was useful for physical therapists to combine open kinetic chain exercises to design appropriate exercises programs for patients.

碩士<br>臺北巿立體育學院<br>運動科學研究所<br>98<br>The purpose of the current study was to investigate the effect of art therapy on stress coping of closed kinetic chain sport athletes with different sport goal orientation. Research intervention was conducted on closed kinetic chain sport athletes of Taipei Physical Education College that 11 participants were in the experimental group and 14 participants were in the control group, and the mean age was 20.32±1.80 years old. Art therapy sessions were conducted 6 times with 2 hours each time for 1.5 months. “Coping Strategies Scale for Competitive Stress” and “Task and Ego Orientation in Sport Questionnaire” were administered, and descriptive statistics and two-way ANOVA were utilized for data analyses. No differences were found between pre and post tests on problem-focused, emotion-focused, and avoidance coping strategies for both the experimental and control groups. Significant difference was found between the two groups on the post test of problem-focused coping strategy, while no difference was found between the two groups on the post tests of emotion-focused and avoidance coping strategies. No difference was found on problem-focused, emotion-focused, and avoidance coping strategies of athletes with different sport goal orientation.

碩士<br>國立體育學院<br>運動傷害防護研究所<br>94<br>Abstract Purpose: The purpose of this study was to analyze the effects on balance, power, and isokinetic strength after three commonly prescribed closed kinetic chain training: the lunge, the squat, and the leg press. Method: Thirty-five healthy male adults were randomly divided three groups into a lunge group, a squat, a leg-press, and a control. The former performed progressive weight training twice a week for eight weeks. All subjects were tested before and after the eight-week training program. A knee isokinetic strength test, a continuous jump test, and a balance test were used to determine the training effects. Result: The lunge group were significantly higher than the control group in the quadriceps concentric peak torque at 60°/sec. The lunge group and the squat group were significantly higher than the control group in the quadriceps eccentric peak torque at 60°/sec. No significant differences were found in hamstrings concentric and eccentric peak torque at 60°/sec among the lunge group, the squat group and the leg press group. The leg-press group is significantly better than the control group in the power performance. The lunge group, squat group, and leg-press group were all significantly longer than the control group in the average flight time. There were no significant differences in the balance performance. Conclusions: The lunge exercise was more useful than the squat and leg press in quadriceps concentric and eccentric strength training. The lunge, squat, and leg press exercises were all increasing quadriceps strength. The leg press exercise was more efficient than the lunge and squat exercise in the mechanical power performance. The lunge, squat, and leg press exercises were all to increasing average flight time and power performance.