Effect of open vs. closed kinetic chain exercises in ACL rehabilitation on knee joint pain, laxity, extensor muscles strength, and function: a systematic review with meta-analysis.

Anterior cruciate ligament (ACL) injuries are common among physically active individuals, often requiring ACL reconstruction (ACLR) for recovery. Rehabilitating these injuries involves determining the appropriate timing for initiating open kinetic chain (OKC) exercises. Although OKC exercises are effective post-ACLR, their use in rehabilitation remains a subject of debate. Therefore, this study aims to conduct a systematic review to determine whether OKC or closed kinetic chain (CKC) exercises result in differences in laxity, strength of the knee extensor muscle group, function, and functional performance in ACL rehabilitation. Five electronic databases were searched for randomized controlled between-group trials (RCTs). Two reviewers independently evaluated the risk of bias using the PEDro scale. We performed a meta-analysis using a random-effects model or calculated mean differences (fixed-effect) where appropriate. Certainty of evidence was judged using the GRADE approach. The systematic literature search yielded 480 articles, of which 9 met the inclusion criteria. The evidence for all outcomes ranged from very low to low certainty. Across all comparisons, inconsistent results were found in outcome measures related to knee function between OKC and CKC exercises post-ACLR. A significant increase in quadriceps isokinetic strength was found in post-ACLR and ACL-deficient knees in favor of OKC exercises at 3 (p = 0.03) and 4 (p = 0.008) months, respectively. A significant decrease in knee laxity was observed in ACL-deficient knees in favor of OKC at 10 weeks (p = 0.01), although inconsistency was noted at 4 months. Finally, a significant decrease in pain was found in favor of early OKC compared to late OKC (p < 0.003). Additionally, in ACL-deficient knees, low load resistance training (LLRT) OKC showed no significant laxity difference compared to controls (p > 0.05). In contrast, high load resistance training (HLRT) OKC had less laxity than controls at 6 weeks (p = 0.02) but not at 12 weeks (p > 0.05). OKC exercises appear to be superior to CKC for improving quadriceps strength 3-4 months post-injury, whether as a part of conservative or post-surgery rehabilitation. On the other hand, OKC exercises seem to be either superior or equally effective to CKC for improving knee laxity, thus presenting their importance in being included in a rehabilitation protocol from the initial phase. Systematic Review Registration: PROSPERO [CRD42023475230].

Intrinsic graft laxity variation with open kinetic chain exercise after anterior cruciate ligament reconstruction: A non-randomized controlled study.

OBJECTIVES: To determine whether quadriceps and hamstring strengthening in a rehabilitation program involving early open kinetic chain (OKC) and/or closed kinetic chain (CKC) knee joint exercises had an influence on graft laxity at 1, 3, and 6 months after anterior cruciate ligament reconstruction (ACLR). DESIGN: Retrospective study. METHODS: Two groups (n = 53) of ACLR patients (combination of OKC and CKC exercises group compared to a CKC exercise group) were recruited. OKC protocol was introduced at 2 weeks post-operatively without external resistance and progressed at 4 weeks with load. Comparative ACL graft laxity measurement and isokinetic strength testing were prospectively performed up to 6 months in both groups. RESULTS: No significant differences were observed in the knee laxity at 1 (p = 0.263), 3 (p = 0.263), and 6 months (p = 0.256) follow up between the groups. Similarly, no significant results were observed in within-group knee laxity between 1 and 6 months after ACLR in the intervention (p = 0.155) and control group (p = 0.690). CONCLUSION: The early initiation of OKC along with CKC exercises doesn't seem to increase the ACLR graft laxity as compared to a rehabilitation program with only CKC exercises.

Evaluation of Muscle Strength and Graft Laxity With Early Open Kinetic Chain Exercise After ACL Reconstruction: A Cohort Study.

Background: Open kinetic chain (OKC) exercise is an effective method to improve muscle function during rehabilitation after anterior cruciate ligament reconstruction (ACLR); however, there is controversy about its use in the early phase of rehabilitation. Purpose: To determine (1) whether the use of OKC and closed kinetic chain (CKC) exercises improves quadriceps and hamstring strength in the early phase of rehabilitation after ACLR and (2) whether the early use of OKC exercise affects graft laxity at 3 and 6 months postoperatively in patients with a hamstring tendon graft. Study Design: Cohort study; Level of evidence, 3. Methods: This study included an intervention group that underwent OKC + CKC exercises (n = 51) and a control group that underwent CKC exercise only (n = 52). In the intervention group, OKC exercise for the quadriceps and hamstring was started at 4 weeks after ACLR. At 3 and 6 months postoperatively, isokinetic testing was performed to calculate the limb symmetry index (LSI) and the peak torque to body weight ratio (PT/BW) for the quadriceps and hamstring. Anterior knee laxity was measured by an arthrometer. Results: At 3 and 6 months postoperatively, quadriceps strength was higher in the intervention group than in the control group for the LSI (3 months: 76.14% ± 0.22% vs 46.91% ± 0.21%, respectively; 6 months: 91.05% ± 0.18% vs 61.80% ± 0.26%, respectively; P < .001 for both) and PT/BW (3 months: 1.81 ± 0.75 vs 0.85 ± 0.50 N·m/kg, respectively; 6 months: 2.40 ± 0.73 vs 1.39 ± 0.70 N·m/kg, respectively; P < .001 for both). There were similar findings regarding hamstring strength for the LSI (3 months: 86.13% ± 0.22% vs 64.26% ± 0.26%, respectively; 6 months: 91.90% ± 0.17% vs 82.42% ± 0.24%, respectively; P < .001 at three months, P = .024 at 6 months) and PT/BW (3 months: 1.09 ± 0.36 vs 0.67 ± 0.39 N·m/kg, respectively; 6 months: 1.42 ± 0.41 vs 1.07 ± 0.39 N·m/kg, respectively; P < .001 for both). No significant difference in laxity was observed between the intervention and control groups at 3 or 6 months. Conclusion: Early use of OKC exercise for both the quadriceps and the hamstring, in addition to conventional CKC exercise, resulted in better correction of quadriceps and hamstring strength deficits without increasing graft laxity.

Proximal to distal sequencing impacts on maximum shoulder joint angles and the risk of impingement in baseball pitching involving a scapular independent thoracohumeral model.

BACKGROUND: Hyperangulation of the scapulohumeral joint due to poor coordination of the scapula during throwing motion is claimed to be a major cause of internal impingement in baseball pitchers. However, evidence of injurious scapular kinematics is lacking, particularly regarding how hyperangularion actually occurs in full-effort pitching. The purpose of this study was to describe sequential scapular motions involved in attaining maximum joint angles during pitching and the implications for internal impingement in elite baseball pitchers. METHODS: An electromagnetic goniometer system computed kinematics for pelvis, thorax, scapulae, arms, and forearms during baseball pitching in 72 pitchers. Internal impingement risk was assessed based on kinematic characteristics of internal impingement quantified in a cadaveric study. RESULTS: The pelvis, thorax, and scapula rotated in the proximal-to-distal sequence. Large forearm layback observed near the end of the cocking phase (182 ± 27°) was achieved with a submaximal scapulohumeral external rotation (98 ± 14°). In the next 0.027 ± 0.007 s, forward thoracic rotation and then scapular rotation caused increased scapulohumeral external rotation to a maximum of 113 ± 14°. Here, humeral horizontal adduction and scapula protraction occurred simultaneously preventing the humerus from lagging further behind the scapula. Only one participant reached critical hyperangulation beyond which internal impingement was reported to occur. CONCLUSION: Most elite pitchers safely attained the fully cocked position, yet off-timed recoiling of scapular protraction caused hyperangulation in full-effort pitching. Therefore, proximal-distal sequencing between the scapula and humerus should be evaluated to lessen the risk of internal impingement in baseball pitchers.

Loaded open-kinetic-chain exercises stretch the anterior cruciate ligament more than closed-kinetic-chain exercises: In-vivo assessment of anterior cruciate ligament length change.

BACKGROUND: Usage of open-kinetic-chain (OKC) or closed-kinetic-chain (CKC) exercises during rehabilitation planning after anterior cruciate ligament (ACL) reconstruction has been debated for decades. However, the ACL elongation pattern during different rehabilitation exercises at different loadings remains unclear. OBJECTIVES: This study aimed to determine the effects of OKC and CKC exercises on the length of ACL anteromedial bundle (AMB) and posterolateral bundle (PLB) to provide biomechanical support for making rehabilitation schedules. DESIGN: Laboratory Descriptive Study. METHOD: Eighteen healthy volunteers were asked to perform two OKC motions, including non-weight-bearing and 10 kg loaded seated knee extension (OKC-0, OKC-10), as well as two CKC motions, including box squat (BS) and deep single-legged lunge (Lunge). Techniques of 2D-to-3D image registration and 3D ligament simulation were used to quantify length changes of ACL. RESULTS: The motion which led to the least and most ACL elongation were OKC-0 and OKC-10, respectively. The AMB and PLB were significantly longer in OKC-10 than those in OKC-0 during 0-60° and 0-55° of knee flexion (p < 0.01). Compared with reference length, the AMB and PLB were stretched during 0-30° and 0-10° respectively during OKC-10. During CKC exercises, the AMB and PLB were also stretched from 0 to 25°and 0-5°, respectively. Additionally, no significant difference was found in the length change of ACL bundles between BS and lunge. CONCLUSIONS: OKC-0 may be safe for the rehabilitation program after ACL reconstruction, and loaded exercises shall be applied when restricted with >30° in early-stage rehabilitation.

Comparison of screw-home movement between patients with knee osteoarthritis and normal adults.

BACKGROUND: Tibial rotation accompanying sagittal movement contains the phenomenon of screw-home movement (SHM) of the knee, which plays an important role in knee stability during extension. OBJECTIVE: This study aimed to investigate the change of SHM in patients with knee osteoarthritis (OA). METHODS: Thirty-one sex-matched patients with knee OA and 31 normal subjects were recruited. The total tibial rotation was obtained during knee sagittal movement (extension and flexion) using an inertial measurement unit. The acquired angle of tibial rotation was divided into eight periods. The total tibial rotation and the variation of each period were compared between the OA and control groups. The difference in tibial rotation according to Kellgren-Lawrence (KL) grade was compared. RESULTS: The total tibial rotation of the OA group decreased compared with the control group during knee extension and flexion (P< 0.001). Variations of tibial rotation were significantly different between groups in all periods (P< 0.001) except for knee extension at 70∘ to 45∘ (P= 0.081). There was no significant difference in tibial rotations among the KA grades of OA patients. CONCLUSION: We found a reduction in the total tibial rotation and loss of the SHM in the unloaded OA knee. It could be predicted that reduced SHM appeared early in knee OA.

In-vivo tibiofemoral kinematics of the normal knee during closed and open kinetic chain exercises: A comparative study of box squat and seated knee extension.

A rehabilitation program after anterior cruciate ligament reconstruction is of great importance to obtain a satisfactory prognosis after surgery. However, there is still an onging debate over whether closed kinetic chain or open kinetic chain exercises should be chosen. Our study was designed to compare the in vivo tibiofemoral kinematics during closed kinetic chain and open kinetic chain exercises. Eighteen healthy volunteers were asked to perform box squat and unloaded/10 kg-loaded seated knee extension. In vivo 3-dimensional analysis of tibiofemoral kinematics of different motions were determined using a dual fluoroscopic imaging system. The study found significantly more tibial anterior displacement during loaded seated knee extension than during unloaded seated knee extension from 25°-50° of knee flexion (p ≤ 0.031). The knees exhibited significantly more internal tibial rotation and lateral tibial translation during the box squat than both seated knee extensions during mid-flexion. In addition, the knees showed less internal-external (IE) range of motion (ROM) from 20°- 75° of flexion (p < 0.001) and medial-lateral (ML) ROM from 75° to full extension (p ≤ 0.006) during box squat than both extensions. This knowledge may help optimize rehabilitation plans for patients post ACL reconstruction.

Intraoperative knee kinematics measured by computer-assisted navigation and intraoperative ligament balance have the potential to predict postoperative knee kinematics.

This study was designed to analyze the effects of type of activity and cruciate ligament resection on knee kinematics and ligament balance after total knee arthroplasty (TKA), and to determine if intraoperative passive kinematics are associated with active kinematics. Fresh-frozen human cadaveric knees were examined. The knees were mounted on a quadriceps-driven simulator. Cruciate-retaining (CR-TKA) and posterior-substituting (PS-TKA) TKA was performed using a contemporary knee system. Active flexion (closed-kinetic chain [CKC] and open-kinetic-chain [OKC]) and passive flexion were analyzed by recording the knee kinematics using a specifically developed application of an imageless navigation system. An electronic ligament balancer was used to measure the tibiofemoral gap under constant distraction pressure. The femur rotated externally relative to the tibia during passive and active CKC flexion. The femur translated anteriorly from 10° to 50° of flexion after TKA. Beyond 50° of flexion, the femur translated posteriorly in all surgical conditions. The femoral location during active CKC flexion was posterior relative to that during active OKC. Femoral rotation and translation during passive knee flexion correlated significantly with that during active knee flexion. Posterior tilt of the electronic ligament balancer was greater with CR-TKA than with PS-TKA and correlated significantly with the anteroposterior position of the femur. Statement of Clinical Significance: Intraoperative knee kinematics measured by computer-assisted navigation and intraoperative ligament balance have the potential to predict postoperative knee kinematics.

ACL Reconstruction Rehabilitation: Clinical Data, Biologic Healing, and Criterion-Based Milestones to Inform a Return-to-Sport Guideline.

CONTEXT: Anterior cruciate ligament (ACL) reconstruction (ACLR) and postoperative rehabilitation continues to be a multidisciplinary focus in both research and clinical environments. Recent research on ACLR warrants a reexamination of clinicians' current rehabilitation practices to optimize the strikingly variable clinical outcomes after ACLR and return to sport. The purpose of the article and updated guidelines is to use contemporary evidence to systematically revisit our practice guidelines and validate our clinical milestones with data from our university-based practice. EVIDENCE ACQUISITION: Using the PubMed search engine, articles that reported on ACLR rehabilitation and protocols, guidelines, graft type, healing and strain, return to sport, psychological considerations, and secondary injury prevention published from 1979 to 2020 were identified using the search terms ACLR protocols, guidelines, ACLR rehabilitation, ACL graft, ACL open kinetic chain (OKC) exercise and closed kinetic chain (CKC) exercise, ACLR return to sport, ACLR psychological factors, and ACL injury prevention. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 5. RESULTS: Clinical milestones after ACLR were validated using clinical data collected from 2013 to 2017 at a university-based practice. Variables including knee joint range of motion, effusion, Knee Outcome Survey-Activities of Daily Living Scale, and quadriceps strength index were tracked throughout rehabilitation and analyzed to help inform an updated ACLR rehabilitation guideline. CONCLUSION: Incorporating the latest research, combined with direct clinical data, provides a current, realistic, and clinically benchmarked strategy for ACLR rehabilitation. Commonly held clinical beliefs regarding rehabilitation after ACL injury must be challenged by the latest research to improve patient outcomes and decrease the risk of reinjury. Key updates to the practice guidelines include the use of frequent and accurate quadriceps strength testing, delayed return-to-sport timeline, immediate use of open kinetic chain exercise, criterion-based progressions for running, sprinting, plyometrics, agility, cutting/pivoting, return to competition, and the inclusion of a secondary prevention program after return to sport. STRENGTH OF RECOMMENDATION TAXONOMY (SORT): B.

The effectiveness of blood-flow restricted resistance training in the musculoskeletal rehabilitation of patients with lower limb disorders: A systematic review and meta-analysis.

OBJECTIVE: This meta-analysis aimed to evaluate the effectiveness of low-load Resistance Training (RT) with or without Blood Flow Restriction (BFR) compared with conventional RT on muscle strength in open and closed kinetic chains, muscle volume and pain in individuals with orthopaedic impairments. DATA SOURCES: Searches were conducted in the PubMed, Web of Science, Scopus and Cochrane databases, including the reference lists of randomised controlled trials (RCT's) up to January 2021. Review method: An independent reviewer extracted study characteristics, orthopaedic indications, exercise data and outcome measures. The primary outcome was muscle strength of the lower limb. Secondary outcomes were muscle volume and pain. Study quality and reporting was assessed using the TESTEX scale. RESULTS: A total of 10 RCTs with 386 subjects (39.2 ± 17.1 years) were included in the analysis to compare low-load RT with BFR and high or low-load RT without BFR. The meta-analysis showed no significant superior effects of low-load resistance training with BFR regarding leg muscle strength in open and closed kinetic chains, muscle volume or pain compared with high or low-load RT without BFR in subjects with lower limb impairments. CONCLUSION: Low-load RT with BFR leads to changes in muscle strength, muscle volume and pain in musculoskeletal rehabilitation that are comparable to conventional RT. This appears to be independent of strength testing in open or closed kinetic chains.

Open and closed kinetic chain exercises for meniscus lesions / 中国组织工程研究

BACKGROUND: Both open and closed kinetic chain exercises can be applied to meniscal lesions in the knee joint, but their mechanisms are different. There is still no clinical report on the improvement of meniscus lesions by the two exercise methods OBJECTIVE: To observe the effects of open kinetic chain exercise and closed kinetic chain exercise on meniscus lesions in young patients. METHODS: Forty-nine young patients with meniscus lesions were treated with rehabilitation and conservative treatments. They were randomly divided into two groups using a random digital table method: A biofeedback open kinetic chain group (n=25) treated with basic therapy combined with terminal knee extension biofeedback training, and a leg press closed kinetic chain group (n=24) treated with basic therapy combined with single-leg press training. The basic treatment included electro-acupuncture, manipulation therapy and unarmed exercise therapy. Biofeedback open chain training was conducted with Myotrac infiniti biofeedback instrument produced by Thought, Canada. Closed chain training with leg press was conducted using pedal accessories of GYM80 intelligent strength training system, Germany. All the trainings were conducted once a day for 3 consecutive weeks. Curative effects were assessed by joint range of motion (ROM) during knee joint flexion and extension, total ROM, visual analogue scale score, modified Lysholm knee score, and activity of daily living score. The study protocol was implemented in line with the relevant requirements of Sichuan Provincial Orthopedic Hospital. All the patients were informed of the study procedures. RESULTS AND CONCLUSION: Assessment for ROM: After treatment, the ROM during joint flexion and extension and total ROM in the biofeedback open kinetic chain group were significantly better than the baseline (P 0.05). Assessment for pain and function: The two groups had statistically significant improvements on visual analogue scale score, modified Lysholm knee score, and activity of daily living score after treatment (P < 0.05). Compared with the biofeedback open kinetic chain group, the activity of daily living score was higher in the leg press closed kinetic chain group (P < 0.05). The two groups had satisfactory effects on the knee joint ROM, pain and functional performance. Therefore, biofeedback open kinetic chain exercise has a better improvement on the knee joint ROM, while the leg press closed kinetic chain exercise shows better outcomes in the improvement of knee functional performance and activity of daily living based on the basis of pain control.

Comparisons of Accuracy of Knee Joint Motion During Closed verse Open Kinetic Chain Tasks in Subjects with Flexible Flatfeet

PURPOSE: This study examined the effects of flexible flatfeet on the accuracy of knee joint motions in closed and open kinetic chain tasks. METHODS: Twenty-four healthy participants were recruited for this study. The subjects were divided into two groups using a navicular drop (ND) test: flexible flatfoot group (n=12, male: 6, aged 22.00±2.22 years) and age-matched control group (n=12, males: 6, aged 22.17±1.53 years). The accuracy of knee motion was measured quantitatively by tracing through the flexion and extension motion of the knee joints in the closed kinetic chain and the open kinetic chain. RESULTS: There was a significant difference in the accuracy index between the groups in closed kinetic chain task, but there was no significant difference in the open kinetic chain task. In addition, there was a significant difference in the accuracy index between the closed kinetic chain and the open kinetic chain task in the flexible flatfoot group. In addition, a significant negative correlation was observed between the ND and accuracy index in the closed kinematic chain task, but there was no significant relationship between the ND and accuracy index in the open kinematic chain task. CONCLUSION: Flexible flatfeet can affect the accuracy of the adjacent joints, such as the knee joint in the closed kinematic chain.

Effect of Various Movements on Shoulder External Rotators / 中国康复理论与实践

Objective To investigate the activities of infraspinatus (IS) and posterior deltoid (PD) under shoulder external rotation at open kinetic chain (OKC) and closed kinetic chain (CKC) exercise with shoulder abduction 0° and 90° to determine the optimal external rotation rehabilitation exercise.Methods From April to June, 2018, 19 healthy adults finished the movement of 0° OKC, 0° CKC, 90° OKC and 90°CKC. The root mean square (RMS) of IS and PD was recorded with surface electromyography (sEMG), then the standardized RMS (RMS％), ratio of IS/PD and onset time of activation were calculated.Results RMS％ of PD was the minimal at 90° CKC, and was less than that of 0° CKC (P ＜ 0.05). IS/PD was the most at90° CKC, and was more than that of 90° OKC (P ＜ 0.05). The onset time of IS was the earliest in 90° CKC, and earlier than that of 90° OKC (P ＜ 0.05) and 0°OKC (P ＜ 0.05). The onset time of PD was the latest in 0° CKC, and latter than that of 90° OKC (P ＜ 0.05).Conclusion 90°CKC activates IS mostly and earliest, which can be used in early rehabilitation for rotator cuff injury.

The impact of closed versus open kinetic chain exercises on osteoporotic femur neck and risk of fall in postmenopausal women.

[Purpose] This study aimed to investigate how closed and open kinetic chain exercises differed in their impact on bone mineral density (BMD) and fall risk in postmenopausal women with osteoporosis. [Subjects and Methods] The research sample consisted of 40 postmenopausal women with osteoporosis with ages between 51 and 58 years old. They were divided at random into two groups of 20 each, respectively receiving closed and open kinetic chain exercises. These exercises were administered three times per week over a period of four sequential months. Prior to and following the treatment, Dual X-ray Absorptiometry (DEXA) was used to measure the BMD of the femur neck in every participant, while the Biodex Stability System (BSS) was used to estimate how likely each participant was to sustain a fall. [Results] The strongest effect on BMD and fall risk was recorded by the closed kinetic chain exercise. [Conclusion] Osteoporotic postmenopausal women should be prescribed closed kinetic chain exercise to diminish the effects of the disease and minimise their risk of fall.

The effects of open and closed kinetic chain exercises on the static and dynamic balance of the ankle joints in young healthy women.

[Purpose] The purpose of the present study was to analyze the effects of open kinetic chain and closed kinetic chain exercises on the static and dynamic balance of ankle joints in young healthy women. [Subjects and Methods] Twenty women in their 20s were randomly assigned to two groups of ten women each: an open kinetic chain exercise group and a closed kinetic chain exercise group. Each group performed five sets of exercises three times per week for four weeks. Exercise intensity was increased once after two weeks. The subjects' Romberg's test results and their limits of stability were measured to evaluate their static and dynamic balance. The data were analyzed using a two-way repeated measures analysis of variance test. [Results] In the results of Romberg's test, the main effect of the time showed a significant difference in the trace length with eyes closed (Effect size: d=0.97). In the result of limits of stability, the interaction effect showed a significant difference in the backward, and the main effect of the group showed a significant difference in the forward. [Conclusion] The open kinetic chain and closed kinetic chain exercises both improved the balance of the subjects. The closed kinetic chain exercise was more effective at improving the dynamic balance of young healthy women than the open kinetic chain exercise.

The effect of exercise types for rotator cuff repair patients on activities of shoulder muscles and upper limb disability.

[Purpose] This study investigated the effect on activities, shoulder muscle fatigue, upper limb disability of two exercise types performed by patients in the post- immobilization period of rotator cuff repair. [Subjects and Methods] The intervention program was performed by 20 patients from 6 weeks after rotator cuff repair. Ten subjects each were randomly allocated to a group performing open kinetic chain exercise and a group preforming closed kinetic chain exercise. Muscle activity and median frequency were measured by using sEMG and the Upper Extremity Function Assessment before and after conducting the intervention and changes in the results were compared. [Results] There was a significant within group increases in the activities of the shoulder muscles, except for the posterior deltoid. The median power frequencies (MFD) of the supraspinatus, infraspinatus and anterior deltoid significantly increased in the open kinetic chain exercise group, but that of the posterior deltoid decreased. There were significant differences in the changes in the upper limb disability scores of the two groups, in the shoulder muscle activities, except for that of the posterior deltoid, in the comparison of the change in the muscle activities of the two groups, and in the MDFs of all shoulder muscles. [Conclusion] The Median power frequencies of all these muscles after closed kinetic chain exercise increased indicating that muscle fatigue decreased. Therefore, research into exercise programs using closed kinetic chain exercises will be needed to establish exercise methods for reducing muscle fatigue.

Effects of combined open kinetic chain and closed kinetic chain training using pulley exercise machines on muscle strength and angiogenesis factors.

[Purpose] This study investigated the effects of combined open kinetic chain and closed kinetic chain training using pulley exercise machines on muscle strength, anaerobic power, and blood levels of angiogenesis factors. [Subjects and Methods] Twenty male university students were equally divided between control and pulley training groups. The pulley-training group underwent 8 weeks of combined training. Open kinetic chain training consisted of 2 sets of 10 repetitions at 60% of one repetition maximum; closed kinetic chain training consisted of 2 sets of 10 repetitions of resistance exercise using the subject's own body weight. Isokinetic strength (trunk and knee), anaerobic power, vascular endothelial growth factor, angiopoietin-1, angiopoietin-2, and follistatin were analyzed. [Results] After 8 weeks, flexor and extensor muscle strength significantly increased in the trunk and knee; average and peak power also increased significantly. Angiopoietin 1 increased 25% in the control group and 48% in the pulley training group; vascular endothelial growth factor and follistatin increased significantly in the pulley-training group after 8 weeks. [Conclusion] Eight weeks of combined training using pulley exercise machines effectively increased biochemical factors related to muscle growth, as well as muscle strength in the trunk and knees.

Long term effect of selective muscle strengthening in athletes with patellofemoral pain syndrome.

BACKGROUND AND AIM OF THE WORK: The purpose of the study was to examine the long term effects of a selective muscle strengthening program in reducing pain and improving knee function and strength in athletes with Patellofemoral Pain Syndrome. METHODS: A total of one hundred and thirty four athletes were enrolled in the study. All patients were evaluated with Isokinetic Test, Cincinnati Knee Rating System and Visual Analogue Scale. The selective muscle strengthening consisted of 8 weeks of exercises performed 3 times in the first 4 weeks and twice in the last 4 weeks. The muscle strengthening program was performed between 30-90° of knee flexion. During the first 4-weeks treatment we used closed kinetic chain exercises with 3 sets of 8 repetitions at 80% of maximum load. In the last 4-weeks we added open kinetic chain exercises at 70% of maximum load with 3 sets and 10 repetitions to improve the resistance. RESULTS: Analyzing data at the beginning and at the end of the treatment for Isokinetic test, Cincinnati and Visual Analogue Scale we observed a significant scores improvement. At 1 year follow-up the clinical improvements were maintained and everyone followed the recommended program because did not perform the maintenance program. At 2 years follow-up no athletes presented relapses; only four patients were excluded from program. CONCLUSIONS: We believe that our program of selective muscle strengthening should resolve pain and improve knee function and strength as results in obtained scores and could be critical to avoid painful relapses.

Open and closed kinetic chain exercises promote the recovery of function after anterior cruciate ligament reconstruction / 中华物理医学与康复杂志

Objective To compare the clinical effects of open kinetic chain (OKC) exercises with those of closed kinetic chain (CKC) exercises and limited open kinetic chain combined with closed kinetic chain exercises on rehabilitation after the anterior cruciate ligament reconstruction.Methods Ninety-four patients recovering from single-bundle anterior ligament reconstructions were enrolled and randomly divided into an OKC group (n =33),a CKC group (n =30) or a limited open kinetic chain combined with closed kinetic chain group (combined group) (n =31).Lysholm score,International Knee Documentation Committee (IKDC) score,KT-1000,and active and passive range of motion were evaluated for the 3 groups three and six months after the surgery.Results Three months after surgery,significant differences were found among the 3 groups in Lysholm scores [(87.00±4.79),(83.67± 3.55) and (86.71±3.62) respectively],IKDC scores [(89.45±4.79),(86.40±3.76) and (88.58±3.60) respectively],KT-1000[(1.99±0.30),(1.05±0.26) and (1.02±0.24) mm],as well as active and passive range of motion [(10.06±2.06),(7.73±1.41) and (8.10±1.35) mm;(9.76±2.26),(7.87±1.89) and (8.39±1.62) mm] (P＜ 0.05).Six months after surgery,no significant differences were found in Lysholm scores and IKDC scores(P＞0.05),but significant differences were found in KT-1000,and active and passive range of motion(P＜0.05) compared to those at 3 months after surgery.Moreover,there were no significant differences between the OKC and combined groups in Lysholm scores and IKDC scores(P＞0.05),but significant differences between them in active and passive range of motion (P＜0.05).There were no significant differences between the CKC and combined groups in Lysholm scores,IKDC scores,KT-1000,and active and passive range of motion(P＜0.05).Conclusion Combining limited open kinetic chain exercise with closed kinetic chain exercise is safe and reliable in the rehabilitation after anterior cruciate ligament reconstruction.

Difference between adolescent and collegiate baseball pitchers in the kinematics and kinetics of the lower limbs and trunk during pitching motion.

The purpose of this study was to clarify the differences between adolescent and collegiate baseball pitchers in the kinematic and kinetic profiles of the trunk and lower limbs during the pitching motion. The subjects were thirty-two adolescent baseball pitchers aged 12-15 years (APG) and thirty collegiate baseball pitchers aged 18-22 years (CPG). Three-dimensional motion analysis with a comprehensive lower-extremity model was used to evaluate kinematic and kinetic parameters during baseball pitching. The ground reaction forces (GRFs) of the pivot and stride legs during pitching were determined using two multicomponent force plates. The joint torques of hip, knee, and ankle were calculated by the inverse-dynamics computation of musculoskeletal human models using motion-capture data. To eliminate any effect of variation in body size, kinetic and GRFs data were normalized by dividing them by body mass. The velocity of a pitched ball was significantly higher (p < 0.01) in CPG (35.2 ± 1.9 m·s(-1)) than in the APG (30.7 ± 2.7 m·s(-1)). Most kinematic parameters for the lower limbs were similar between the CPG and the APG. Maximum Fy (toward the throwing direction) on the pivot leg and Fy and resultant forces on the stride leg at ball release were significantly greater in the CPG than in the APG (p < 0.05). Hip and knee joint torques on the lower limbs were significantly greater in the CPG than in the APG (p < 0.05). The present study indicates that the kinematics of lower limbs during baseball pitching are similar between adolescent and collegiate pitchers, but the momentum of the lower limbs during pitching is lower in adolescent pitchers than in collegiate ones, even when the difference in body mass is considered. Key pointsCollegiate baseball pitchers can generate the hip and knee joint torques on the pivot leg for accelerating the body forward.Collegiate baseball pitchers can generate the hip and knee joint torques to control/stabilize the stride leg in order to increase momentum on the stride leg during the arm acceleration phase.The kinematics of the lower limbs during baseball pitching are similar between adolescent and collegiate pitchers, but the momentum of the lower limbs during pitching is lower in adolescent pitchers than in collegiate ones, even when the difference in body mass is considered.Adolescent baseball pitchers cannot generate the hip and knee joint torques in the pivot and stride leg for transfer of the energy of trunk and the arm.