Closed Kinetic Chain Exercises Research Articles

Cadeia cinética aberta versus cadeia cinética fechada na reabilitação avançada do manguito rotador

INTRODUÇÃO: Síndrome do impacto do ombro é uma alteração osteomuscular prevalente que leva a uma redução significativa da saúde e à incapacidade funcional. Esta lesão é causada pelo uso repetitivo dos braços acima da linha do ombro ou condição patológica em que ocorre irritação do tendão supraespinhoso secundária a uma abrasão em sua superfície pelo terço anterior do acrômio. Fisioterapia é, muitas vezes, a primeira opção de tratamento, embora sua eficácia ainda esteja em debate. Clinicamente, a reabilitação em cadeia cinética tem sido eficaz na restauração da função do ombro com bons resultados terapêuticos. OBJETIVOS: Avaliar a efetividade de um protocolo de reabilitação do ombro em cadeia cinética fechada para síndrome de impacto do manguito rotador. MATERIAIS E MÉTODOS: Ensaio clínico randomizado de equivalência com 20 pacientes que apresentam lesão grau I e II de manguito rotador na classificação de Neer. Pacientes foram divididos em dois grupos: grupo I, com protocolo de exercícios em Cadeia Cinética Fechada (CCF), e grupo II, com exercícios em Cadeia Cinética Aberta (CCA). Os pacientes foram submetidos a 20 sessões, três vezes por semana, e foram avaliados quanto à dor, mobilidade ativa, passiva, força muscular, atividade elétrica muscular e funcionalidade. Essa avaliação ocorreu em três momentos: inicialmente, com 10 sessões e ao fim do tratamento. Para a análise estatística, foram utilizadas medidas paramétricas, como o teste t-Student (comparação entre os grupos) e ANOVA para medidas repetidas (comparação dentro de cada grupo), e medidas não paramétricas (Kruskal Wallis e teste de Friedman). RESULTADOS: Ambos os grupos apresentaram resultados significativos quanto aos escores obtidos na escala UCLA e Constant. A mobilidade ativa do ombro lesado aumentou no grupo CCF nos movimentos de flexão (p = 0,01), rotação externa (p = 0,000) e rotação interna (p = 0,000). O movimento de abdução melhorou nos dois grupos (p = 0,02 no grupo CCF e 0,04 no grupo CCA). A força muscular de flexão e abdução mostrou um aumento apenas no grupo CCF, enquanto que nos movimentos de rotação externa e interna esses aspectos foram significativos em ambos os grupos. CONCLUSÃO: Constatou-se que exercícios em CCF apresentam melhoras importantes na mobilidade, funcionalidade e força para os pacientes com síndrome de impacto de ombro.

Clinical trial of step-up exercise therapy using DVD for patients with hip osteoarthritis

Purpose: Efficacy of exercise treatment for osteoarthritis (OA) has been reported controversially. We developed a new exercise program designed as several step-up stages in accordance with patient disease activity, using a digital video disc (DVD). In this study, we analyzed the efficacy of this step-up exercise therapy program using DVD for the hip OA patients. Methods: We prospectively recruited 45 patients (male1, female44) with symptomatic hip OA were included. All participants provided informed consent to the study which was approved by the Institutional Review Board. They were assigned into 2 groups; (1) DVD group in which the patient was instructed to perform exercise by watching specially-developed DVD program, (2) control group in which the patient was instructed to perform exercise by referring to the home exercise instruction documents. The original DVD was developed among the community of the orthopaedic surgeons, physical therapists and the orthopaedic research nurse. On the DVD, the step-up program had 6 stages consisting of 3 OKC (Open kinetic chain) exercise programs and 3 CKC (Closed kinetic chain) exercise programs. Patients were instructed to perform exercise daily for 30-40 minutes by watching DVD, with completing each stage for 2 weeks. All patients received the following assessments at the entry to the study and 3 months later; (1) muscle volume in the lower limb estimated by impedance of living body instrument, (2) muscle strength by dynamometer, (3) gait speed by time up and go test, (4) stability of lower limb by one-legged standing time (up to 120 seconds), and (5) the objective evaluations by Oxford hip score, Health related Quality of life by SF-8 and Self-efficacy (Self-efficacy is defined as people's beliefs about their capabilities to produce designated levels of performance) by General Selfefficacy scale. If the patient had OA in both hips, only one hip with more painful side was included. Results: There were 12 patients (mean age 54.0 years) in the DVD group and 33 patients (51.7) in the control group. At 3 months, time up and go test was significantly improved from 7.4 seconds to 6.9 seconds (p1⁄40.015) in the DVD group and from 7.6 seconds to 7.2 seconds in the control group (p1⁄40.024). The effect size of this improvement was superior in the DVD group. The stability of lower limb by one-legged standing time was significantly improved only in the DVD group from 81.6 seconds to 103.8 seconds (p1⁄40.02). The muscle volume of the lower limbwas not changed significantly in both groups. The muscle strength of hip abduction was significantly improved from 114.2 to 133.2 newton (p1⁄40.031) only in the control group. SF-8(physical), General Self-efficacy, and Oxford hip score showed tendency of improvement in both groups. However, statistically significant improvement was only seen for pain score of Oxford hip score from 11.9 to 9.6 (p1⁄40.002) in the control group. In hearing of impression regarding DVD program, patients had feeling of better understating of program content by movie, or of accelerating effect by synchronization with the instructor's action in the DVD. Conclusions: Physical function and pain of the patients were significantly improved in both DVD and control groups. Although muscle volume and muscle strength were not improved apparently, physical function including the time up and go test and one-legged standing time was improved better in DVD group than control group. The body balance might be improved more by visual education of DVD movie. The patients’ comments were also related with encouragement of correct understanding of exercise using DVD.

Open-or closed-kinetic chain exercises after anterior cruciate ligament reconstruction

Objective To observe the clinical effects of open kinetic chain and closed kinetic chain exercise in the early period of anterior cruciate ligament reconstruction rehabilitation,provide the theoretical and clinical experiences for the early rehabilitation of the anterior cruciate ligament reconstructed knee.Methods From February 2009 to June 2010,60 patients undergoing single-bundle anterior cruciate ligament reconstructions by using hamstring tendon allograft were enrolled in the study,and were divided into two groups:open kinetic chain group(30 cases,30 knees)and closed kinetic chain group(30 cases,30 knees).In accordance with the rehabilitation procedures for six months,no statistically significant differences were found between the two groups in Lysholm scores,International Knee Documentation Committee(IKDC)scores and one-leg hop test preoperative.The active and passive range of notion,Lysholm scores,IKDC scores,one-leg hop test and KT-1000 were evaluated three and six months after surgery.Results Three months after surgery,no significant differences were found in passive range of motion,Lysholm scores,IKDC scores,but significant differences were found in active range of motion,one-leg hop test and KT-1000,and the closed kinetic chain group was significantly better than the open kinetic chain group.Six months after surgery,no significant differences were found in active range of motion,passive range of motion,one-leg hop test,Lysholm scores,IKDC scores,but significant difference in KT-1000,and the closed kinetic chain group was significantly better than the open kinetic chain group.Conclusion Closed kinetic chain exercise is benefit for recovery of muscles strength,proprioception and protect the graft in the early rehabilitation period after anterior cruciate liganent reconstruction. Key words: Anterior cruciate ligament; Rehabilitation; Reconstructive surgical procedures

Muscle Activation of Selected Shoulder Muscles During Unilateral Wall and Bench Press Tasks Under Submaximal Isometric Effort

Controlled laboratory study. To assess the activation of 7 shoulder muscles under 2 closed kinetic chain (CKC) tasks for the upper extremity using submaximal isometric effort, thus providing relative quantification of muscular isometric effort for these muscles across the CKC exercises, which may be applied to rehabilitation protocols for individuals with shoulder weakness. CKC exercises favor joint congruence, reduce shear load, and promote joint dynamic stability. Additionally, knowledge about glenohumeral and periscapular muscle activity elicited during CKC exercises may help clinicians to design protocols for shoulder rehabilitation. Using surface electromyography, activation level was measured across 7 shoulder muscles in 20 healthy males, during the performance of a submaximal isometric wall press and bench press. Signals were normalized to the maximal voluntary isometric contraction, and, using paired t tests, data were analyzed between the exercises for each muscle. Compared to the wall press, the bench press elicited higher activity for most muscles, except for the upper trapezius. Levels of activity were usually low but were above 20% maximal voluntary isometric contraction for the serratus anterior on both tasks, and for the long head triceps brachii on the bench press. Both the bench press and wall press, as performed in this study, led to relatively low EMG activation levels for the muscles measured and may be considered for use in the early phases of rehabilitation.

COMPARATIVE ANALYSIS OF ELBOW JOINT LOADING IN PUSH-UP AND BENCH-PRESS

Upper extremity pain and dysfunction are common orthopedic problems in individuals who practice physical activities involving the upper limbs. Push-ups (PUs) and bench-presses (BPs), representing closed kinetic chain (CKC) and open kinetic chain (OKC) exercises, respectively, are among the most popular training exercises for the upper extremity in sports training and clinical rehabilitation applications. Utilizing a self-developed exercise testing model, the present study examines the difference in elbow joint loading between OKC and CKC exercises of the upper extremity. As many as 15 physically healthy male subjects with an average age of 19.8 years (S.D. 1.4), an average height of 176.8 cm (S.D. 4.2), and an average weight of 69.27 kg (S.D. 5.0) were studied. Each subject was asked to perform two different types of exercise, namely PUs and BPs. The kinematics, kinetics, and muscle activation of the elbow joint were calculated and analyzed using laboratory-developed motion analysis procedures. The PU exercises result in a greater loading on the elbow joint than the BP exercises, but produce a lower muscle activation. OKC exercises yield a greater muscle strengthening effect than CKC exercises. The increased shear stress on the elbow joint should be carefully noted when performing PU exercises. The results presented in this study provide valuable information for treatment and rehabilitation purposes in clinical applications.

The Effect of Closed-Kinetic Chain Exercises and Open-Kinetic Chain Exercise on the Muscle Activity of Vastus Medialis Oblique and Vastus Lateralis

Patellofemoral pain syndrome (PFPS) is one of the most prevalent musculoskeletal conditions of the lower limb. The muscle imbalance between the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles is one of the main factors leading to the development of PFPS. The disparity in research and the necessity to add to the existing literature base led to the development of this study. The aim of this study was to investigate the effect of 2 closed kinetic chain exercises and 1 open kinetic chain exercise on VMO and VL muscle activity. Twenty-two healthy asymptomatic individuals participated in this study. The surface electromyography (EMG) of VMO and VL was measured and used to calculate the VMO:VL ratio during 3 different quadriceps-strengthening exercises (a double leg squat with isometric hip adduction exercise, an open kinetic chain knee extension exercise, and a lunge exercise). The double leg squat with isometric hip adduction exercise was shown to produce a significantly greater VMO:VL ratio (1.14:1) than the other 2 exercises (p = 0.015 and p = 0.005). The open kinetic chain knee extension exercises produced significantly greater activation of VL than the lunge exercise (p = 0.001 and p = 0.036). The lunge exercise produced the VMO:VL ratio (1.18:1) closest to the idealized ratio of 1:1. Potential clinical recommendations can be made proposing the lunge exercise as a key tool in early rehabilitation when restoring preferential VMO:VL ratio is essential. The double leg squat with isometric hip adduction exercise would be useful in maintaining correct patella tracking and selectively strengthening VMO.

The Effects of 6-Week Training Programs on Throwing Accuracy, Proprioception, and Core Endurance in Baseball

With a limited number of outcomes-based studies, only recommendations for strength-training and rehabilitation programs can be made. To determine the extent to which throwing accuracy, core stability, and proprioception improved after completion of a 6-week training program that included open kinetic chain (OKC), closed kinetic chain (CKC), and/or core-stability exercises. A 2 x 3 factorial design. Division III college. 19 healthy baseball athletes with a control group of 15. Two 6-week programs including OKC, CKC, and core-stabilization exercises that were progressed each week. Functional throwing-performance index, closed kinetic chain upper extremity stability test, back-extensor test, 45 degrees abdominal-fatigue test, and right- and left-side bridging test. There was no significant difference between groups. An increase was evident in all pretest-to-posttest results, with improvement ranging from 1.36% to 140%. Both of the 6-week training programs could be used to increase throwing accuracy, core stability, and proprioception in baseball.

Predictors of Functional Task Performance Among Patients Scheduled for Total Knee Arthroplasty

Osteoarthritis (OA) is a common health problem affecting more than 7 million Americans. Declines in strength, flexibility, and knee joint pain reduce functional ability and contribute to decisions for total knee arthroplasty (TKA). This study describes predictors of functional ability among knee patients scheduled for TKA and proposes a preoperative exercise program to improve functional ability. A total of 82 knee OA patients (average age = 62.7 +/- 7.48 years, 70% women) were recruited from a single orthopedic surgeon's office. Muscular fitness assessments included knee flexion, extension strength, and range of motion (ROM) of the surgical and nonsurgical knees. Functional ability was assessed by 6-minute walk, number of chair rises in 30 seconds, and time required to ascend and descend 2 flights of stairs. Perceived functional ability and pain were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index. Correlation matrices determined which measures of muscular fitness, pain, and perceptions were associated with measures of functional ability. Significant correlates were entered into regression equations that determined the significant predictors of the functional tasks. These regression equations identified flexion strength of the nonsurgical knee as predicting 24-45% of the variance of functional ability assessments that involved independent or consecutive knee movement. Other variables that, to a lesser degree, predicted performance of the functional ability assessments included knee joint ROM and body mass index. Because functional ability after TKA is strongly dependent on presurgical functional ability, future investigators may wish to examine the impact of improving presurgical functional ability of TKA patients through resistance training, particularly closed-kinetic chain exercises that transfer fewer forces through the knee joint.

Fisioterapia em pacientes com síndrome fêmoro-patelar: comparação de exercícios em cadeia cinética aberta e fechada

Este estudo teve como objetivo comparar a eficácia do fortalecimento muscular na recuperação funcional da síndrome fêmoro-patelar (SFP). Foram selecionadas 20 mulheres com SFP divididas em dois grupos: o Grupo 1 (G1) realizou fortalecimento do músculo quadríceps femoral em cadeia cinética aberta (CCA) e o Grupo 2 (G2) em cadeia cinética fechada (CCF), durante oito semanas com freqüência de duas vezes semanais. Foi avaliada a dor, capacidade funcional, flexibilidade, encurtamento dos músculos isquiotibiais, ângulo Q e eletromiografia (EMG) dos músculos vasto medial (VM) e vasto lateral (VL) durante extensão isométrica da perna. Antes e após o tratamento, as variáveis foram analisadas pelo teste de Wilcoxon, e entre os grupos pelo teste t para amostras independentes ou Anova de Friedman ou Manova (a<0,05). Após o tratamento, os resultados mostram que houve melhora da capacidade funcional, encurtamento dos músculos isquiotibiais e flexibilidade. Porém, somente o G1 apresentou diminuição da intensidade da dor e aumento da atividade EMG do músculo VL, enquanto ambos não modificaram o ângulo Q. Os dados sugerem que os tratamentos baseados no fortalecimento do músculo quadríceps femoral possibilitaram melhoras importantes nos principais sinais e sintomas apresentados pelas pacientes, não havendo diferenças evidentes entre os realizados em CCA e CCF.

A Systematic Review of Anterior Cruciate Ligament Reconstruction Rehabilitation –Part II: Open Versus Closed Kinetic Chain Exercises, Neuromuscular Electrical Stimulation, Accelerated Rehabilitation, and Miscellaneous Topics

Anterior cruciate ligament (ACL) reconstruction is a common surgical knee procedure that requires intensive postoperative rehabilitation by the patient. A variety of randomized controlled trials have investigated aspects of ACL reconstruction rehabilitation. A systematic review of English language level 1 and 2 studies identified 54 appropriate randomized controlled trials of ACL rehabilitation. This part of the article discusses open versus closed kinetic chain exercises, neuromuscular electrical stimulation, accelerated rehabilitation, and miscellaneous topics.

Análise da freqüência mediana do sinal eletromiográfico de indivíduos com lesão do ligamento cruzado anterior em exercícios isométricos de cadeia cinética aberta e fechada

Indivíduos com lesão do ligamento cruzado anterior (LCA) possuem importantes alterações funcionais na musculatura periarticular do joelho. Sendo assim, é de suma importância caracterizar tais alterações, bem como enfatizar um efetivo protocolo de reabilitação para esses indivíduos, com conseqüente retorno às atividades físicas. O objetivo deste estudo foi analisar o comportamento da freqüência mediana (Fmed) em indivíduos com lesão do LCA durante contrações isométricas em exercícios de cadeia cinética aberta (CCA) e fechada (CCF). Entre lesados e não lesados, 40 indivíduos realizaram a extensão do joelho através da contração isométrica voluntária máxima (CIVM) nos aparelhos leg extension e leg press a 30°, 60° e 90° de flexão do joelho. Os resultados revelaram valores da Fmed menores para indivíduos com lesão do LCA quando comparados com o membro contralateral e grupo controle em CCA (p < 0,05). Já exercícios em CCF não apresentaram diferença estatística significativa (p > 0,05) na comparação entre os grupos, não evidenciando esse tipo de lesão. Portanto, a Fmed parece ser uma ferramenta eletromiográfica eficaz na caracterização da lesão crônica do LCA. Além disso, exercícios em CCF parecem ser os mais indicados para a reabilitação desses indivíduos.

Comparison of proprioceptive functions between computerized proprioception facilitation exercise and closed kinetic chain exercise in patients with knee osteoarthritis

The aim of this study was to compare proprioceptive function between computerized proprioception facilitation exercise (CPFE) and closed kinetic chain exercise (CKCE) for knee osteoarthritis. Randomized-controlled. Kinesiology laboratory. Eighty-one patients with bilateral knee osteoarthritis were randomly assigned to CPFE, CKCE, and control groups. Both exercise groups underwent an 8-week program of three sessions per week. The control group received no training. The CPFE program included a 20-min computer game to be played by the trained foot of the subject. CKCE included 10 sets of 10 repetitions of repeated knee extension and flexion with resistance of 10-25% of body weight. Absolute reposition error, functional score, walking speed, and knee muscle strength were assessed with an electrogoniometer, the physical function subscale of Western Ontario and McMaster Osteoarthritis Index, a CASIO stopwatch, and a Cybex 6000 dynamometer before and after the 8-week period. The results of this study showed that both CPFE and CKCE were effective in improving joint position sense, functional score, walking speed, and muscle strength. Furthermore, CKCE showed greater effect in increasing knee extensor torque in patients with knee osteoarthritis. Clinical effects of CPFE were the same as those of CKCE except for knee extensor torque. The increase in knee extensor torque in CPFE patients was not as great as that seen in CKCE patients.

The Effect of a Toe-Heel Pedal Exercise Machine

Muscle strengthening exercise in Open Kinetic Chain (OKC) and muscle strengthening exercise in Closed Kinetic Chain (CKC) with a Toe-Heel Pedal Exercise Machine were performed, and were compared the results of knee proprioception tests (threshold test / position sense test). The subjects were 17 patients who had received total knee arthroplasty. They were assigned to either group A (OKC exercise group, n = 9) or group B (CKC exercise group, n = 8). The effect of 3-week exercise therapy was evaluated as the outcome of the knee proprioception tests. In group A, improvement rates were 3.8 ± 6.9% in the threshold test and 7.6 ± 10.7% in the position sense test. In group B, improvement rates were 25.2 ± 4.9% in the threshold test and 27.6 ± 8.2% in the position sense test. Thus, the group of muscle strengthening exercises in CKC with the Toe-Heel Pedal Exercise Machine showed higher improvement rates both in the threshold test and the position sense test.

Open- or Closed-Kinetic Chain Exercises After Anterior Cruciate Ligament Reconstruction?

Open-kinetic chain (OKC) and closed-kinetic chain (CKC) exercises may not differ in their effects on the healing response of the anterior cruciate ligament (ACL)-reconstructed knee. Recent biomechanical studies have shown that the peak strains produced on a graft are similar. Clinical studies suggest that both play a beneficial role in the early rehabilitation of the reconstructed knee.

New Isokinetic Parameters For The Outcome Assessment Of Accelerated Rehabilitation After Anterior Cruciate Ligament Reconstruction

Strengthening of muscle power and restoration of dynamic performance have been emphasized in accelerated rehabilitation after anterior cruciate ligament reconstruction (ACLR). It is necessary to find proper ways to assess the outcome of rehabilitation process, especially in the early stage for better monitoring and adjustment of the rehabilitation process. However, the evaluation of rehabilitation outcome has been confined to the simple increase of isokinetic muscle torque after surgery. PURPOSE To investigate the changes of isokinetic torque curves during the controlled ambulatory phase in patients who received rehabilitation program after ACLR with the effort of finding useful isokinetic parameters on the outcome of accelerated rehabilitation. METHODS Twenty patients with ACL reconstruction (mean age 33 years (23–47), 16 males, 4 females) were randomly divided into two training groups. One (n = 10) was accelerated training (AT) group composed of open and closed kinetic chain(CKC) exercises and the other (n = 10) was conventional training (CT) group consisting of mainly CKC and conditioning exercises. Both groups underwent each assigned exercise program during controlled ambulatory phase from 6 to 12 weeks after surgery in our facility. Various isokinetic parameters at the angular velocity of 180°/sec (peak torque, time to peak torque, angle of peak torque, average power and work fatigue ratio) were obtained at 6 and 12 weeks after surgery. As new parameters to evaluate the dynamic performance of the knee muscles, the ratio of peak torque to time to peak torque (PTR) and the ratios of peak torque to angle from starting to peak torque (PAR) were calculated to determine the changes of torque curves. RESULTS After 6 weeks of training programs, two training groups showed significantly increases of peak torque, total work and average power of knee extensor(p = 0.007 in AT vs 0.009 in CT). However, only AT group showed a significant decrease in time to peak torque (202 ± 69 → 156 ± 37msec, p = 0.024) of knee extensor during this period. PTR (0.303 ± 0.267→0.550 ± 0.327(AT), 0.256 ± 0.148→0.367 ± 0.124(CT)) and PAR (2.17 ± 1.67→3.80 ± 1.91(AT), 1.94 ± 1.00→2.54 ± 0.70(CT)) significantly increased in both training groups. So, the isokinetic time-torque curve and angle-torque curve of the knee extensor shifted to the left and upward side after training. These ratios of AT groups were significantly higher than those of CT group(p = 0.010(PTR), p = 0.005(PAR)). CONCLUSIONS AT group showed more prominent increases of PTR and PAR than CT group. We suggest the PTR and PAR as new parameters to assess the outcome of accelerated rehabilitation after ACLR in the controlled ambulatory phase.

New Isokinetic Parameters For The Outcome Assessment Of Accelerated Rehabilitation After Anterior Cruciate Ligament Reconstruction

Strengthening of muscle power and restoration of dynamic performance have been emphasized in accelerated rehabilitation after anterior cruciate ligament reconstruction (ACLR). It is necessary to find proper ways to assess the outcome of rehabilitation process, especially in the early stage for better monitoring and adjustment of the rehabilitation process. However, the evaluation of rehabilitation outcome has been confined to the simple increase of isokinetic muscle torque after surgery. PURPOSE To investigate the changes of isokinetic torque curves during the controlled ambulatory phase in patients who received rehabilitation program after ACLR with the effort of finding useful isokinetic parameters on the outcome of accelerated rehabilitation. METHODS Twenty patients with ACL reconstruction (mean age 33 years (23–47), 16 males, 4 females) were randomly divided into two training groups. One (n = 10) was accelerated training (AT) group composed of open and closed kinetic chain(CKC) exercises and the other (n = 10) was conventional training (CT) group consisting of mainly CKC and conditioning exercises. Both groups underwent each assigned exercise program during controlled ambulatory phase from 6 to 12 weeks after surgery in our facility. Various isokinetic parameters at the angular velocity of 180°/sec (peak torque, time to peak torque, angle of peak torque, average power and work fatigue ratio) were obtained at 6 and 12 weeks after surgery. As new parameters to evaluate the dynamic performance of the knee muscles, the ratio of peak torque to time to peak torque (PTR) and the ratios of peak torque to angle from starting to peak torque (PAR) were calculated to determine the changes of torque curves. RESULTS After 6 weeks of training programs, two training groups showed significantly increases of peak torque, total work and average power of knee extensor(p = 0.007 in AT vs 0.009 in CT). However, only AT group showed a significant decrease in time to peak torque (202 ± 69 → 156 ± 37msec, p = 0.024) of knee extensor during this period. PTR (0.303 ± 0.267→0.550 ± 0.327(AT), 0.256 ± 0.148→0.367 ± 0.124(CT)) and PAR (2.17 ± 1.67→3.80 ± 1.91(AT), 1.94 ± 1.00→2.54 ± 0.70(CT)) significantly increased in both training groups. So, the isokinetic time-torque curve and angle-torque curve of the knee extensor shifted to the left and upward side after training. These ratios of AT groups were significantly higher than those of CT group(p = 0.010(PTR), p = 0.005(PAR)). CONCLUSIONS AT group showed more prominent increases of PTR and PAR than CT group. We suggest the PTR and PAR as new parameters to assess the outcome of accelerated rehabilitation after ACLR in the controlled ambulatory phase.

CLOSED AND OPEN KINETIC CHAIN STRENGTH TRAINING DOES NOT REDUCE LANDING FORCES IN FEMALE ATHLETES

Female athletes have a 4 times greater incidence of injury to the Anterior Cruciate Ligament (ACL) than males. Research has shown plyometric training can decrease landing forces and increase activity of the hamstring muscles when jumping and landing. Closed kinetic chain strength exercises for the lower extremities recruit both the quadriceps and hamstrings to stabilize the knee joint. When the foot is in contact with the ground, the hamstring muscles act to reduce stress on the ACL. Thus, a strong contraction of the hamstrings and a decrease in landing forces could diminish the likelihood of ACL injuries. PURPOSE The purpose of this study was to determine the effect of open kinetic chain (OKC) and closed kinetic chain (CKC) strength training on landing forces and corresponding electromyographical (EMG) activity of the quadriceps and hamstrings during a stabilization drop. METHODS Thirty female college volleyball players participated in a 6-week periodized training program consisting of either OKC or CKC exercises. Pre- and post-training, the subjects performed a drop stabilization from a 20-inch box onto a forceplate measuring ground reaction forces (GRF) and corresponding times at 200 Hz. Prior to testing, subjects were fitted with surface EMG electrodes on the Rectus Femoris (RF), Vastus Lateralis Oblique (VLO), Biceps Femoris (BF), and Gastrocnemius (GA). EMG data were filtered, rectified and integrated. Paired t-tests were used to compare dependent variables pre- and post-training and alpha was set at p <.05. RESULTS All GRF's remained unchanged in both groups. The time of foot contact to time of Fzpeak was unchanged. Integrated EMG signals increased in RF (.4 + .1v), VLO (.4+.1v), BF (.2+.1), and GA (.8+.3v) for the OKC and in the RF (.3+.1v), VLO (.6+.1v), and GA (.5+.2v) for the CKC. CONCLUSION Six weeks of strength training alone may not reduce landing forces or change neuromuscular patterns to protect the ACL in female athletes.

Electromyographic Comparison of Standard and Modified Closed-Chain Isometric Knee Extension Exercises

The purpose of this study was to compare electromyographic (EMG) activity during open kinetic chain (OKC) and a modified closed kinetic chain (MCKC) knee extension exercises. Both OKC and closed kinetic chain (CKC) exercises provide benefits when devising conditioning programs; however, there are no exercises that combine the benefits of both exercises. Subjects performed maximum isometric knee extensions for both traditional OKC and MCKC knee extension exercises. Surface electrodes were placed on 8 lower-extremity muscles. One second of integrated EMG activity followed 95% maximal knee extension force. The following muscles demonstrated greater EMG activity during the MCKC vs. the OKC knee extension exercises: vastus medialis, medial hamstring, lateral hamstrings, and gluteus maximus. There was no difference between force output between the 2 conditions. This study demonstrates that modifications to traditional OKC exercises demonstrate some characteristics of CKC exercises, and therefore provide another avenue of rehabilitation or strengthening.

Electromyographic Comparison of Standard and Modified Closed-Chain Isometric Knee Extension Exercises

The purpose of this study was to compare electromyographic (EMG) activity during open kinetic chain (OKC) and a modified closed kinetic chain (MCKC) knee extension exercises. Both OKC and closed kinetic chain (CKC) exercises provide benefits when devising conditioning programs; however, there are no exercises that combine the benefits of both exercises. Subjects performed maximum isometric knee extensions for both traditional OKC and MCKC knee extension exercises. Surface electrodes were placed on 8 lower-extremity muscles. One second of integrated EMG activity followed 95% maximal knee extension force. The following muscles demonstrated greater EMG activity during the MCKC vs. the OKC knee extension exercises: vastus medialis, medial hamstring, lateral hamstrings, and gluteus maximus. There was no difference between force output between the 2 conditions. This study demonstrates that modifications to traditional OKC exercises demonstrate some characteristics of CKC exercises, and therefore provide another avenue of rehabilitation or strengthening.

Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises After Anterior Cruciate Ligament Reconstruction

When working with athletes that have recently undergone anterior cruciate ligament (ACL) reconstructive surgery, a common goal of athletic trainers, strength and conditioning coaches, physicians, and physical therapists is to restore quadriceps strength while protecting the reconstructed ACL and patellofemoral joint from unnecessary stresses. Quadriceps strengthening exercises are often referred to as occurring in the open kinetic chain (OKC) or closed kinetic chain (CKC). Currently, there is little agreement in the literature as to whether only CKC exercises or a combination of OKC and CKC exercise should be performed after ACL reconstruction to strengthen the quadriceps. We believe that a combination of OKC and CKC exercises can be used to effectively and safely strengthen the quadriceps after ACL reconstruction. The purposes of this review are to examine the scientific literature currently available for the effects of OKC and CKC exercise on ACL strain and patellofemoral joint stress, and to present a sound rationale for using a combination of OKC and CKC exercises for quadriceps strengthening after ACL reconstruction. On the basis of our review, both OKC and CKC exercises can be modified and implemented for quadriceps strengthening after ACL reconstruction without ausing excessive ACL strain or patellofemoral joint stress.