Who's Afraid of the Big Bad Wolf? Open-Chain Exercises After Anterior Cruciate Ligament Reconstruction

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].

Nurse-Assisted Rehabilitation Protocols Following Anterior Cruciate Ligament Reconstruction

Despite significant advancements in surgical instruments and operation skills, short- and long-term outcomes following anterior cruciate ligament reconstruction (ACLR) remain unsatisfactory, as many patients fail to return to their pre-injury level of sports. Inadequate ACL rehabilitation is the primary cause of poor outcomes. Nurses have become a crucial element in the rehabilitation process. Although there is no consensus regarding the optimal post-operative rehabilitation protocols, restoring muscle strength and neuromuscular control are consistently the primary goals. This literature review presents nurse-assisted rehabilitation protocols aiming at improving muscle strength and neuromuscular control. The review discusses postoperative rehabilitation, including home-based and supervised rehabilitation, open and closed kinetic chain exercises, eccentric and concentric training, blood flow restriction training, and plyometric training. Each training protocol has its benefits and drawbacks, and should be used cautiously in specific stages of rehabilitation. Neuromuscular training, such as neuromuscular electrical stimulation, neuromuscular control exercises, and vibration therapy, is considered crucial in rehabilitation.

Clinical practice and barriers among Swiss physiotherapists treating patients with anterior cruciate ligament reconstruction: A survey of pre-operative rehabilitation to return to sport

OBJECTIVES

To investigate current clinical practice of Swiss physiotherapists treating patients with anterior cruciate ligament reconstruction (ACLR) from pre-operative rehabilitation until return to sport (RTS). We assessed optimisation strategies in daily practice and the perceived barriers to these optimisations, and evaluated whether there was a relevant difference in clinical practice for physiotherapists with post-graduate certification in sports physiotherapy or deep clinical experience and those without such experience.

DESIGN

Cross-sectional survey.

SETTING

Online survey platform.

PARTICIPANTS

Swiss physiotherapists.

MAIN OUTCOME MEASURES

The survey comprised six sections: participant information, pre-operative rehabilitation, post-operative rehabilitation, RTS, re-injury prevention, and optimisation strategies and barriers.

RESULTS

A minority of physiotherapists treated ACLR patients pre-operatively. Overall, 91% included quadriceps open kinetic chain exercise in their treatment, 37% used patient-reported outcomes measures (PROMs) and 39% considered psychological criteria when making decisions about RTS. Most physiotherapists (67%) felt limited due to the time available, the number of prescriptions and the tariffication system.

CONCLUSION

This study highlights areas within ACLR rehabilitation practice in Switzerland that could be improve. Improvements in understanding of the barriers to implementation of best evidence in practice and a redefinition of the clinical process around ACLR rehabilitation in Switzerland are necessary.

Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria).

Quadriceps Dysfunction Following Joint Preservation Surgery: A Review of the Pathophysiologic Basis and Mitigation Strategies

PURPOSE OF REVIEW

To characterize quadriceps muscle dysfunction associated with knee joint preservation surgery, with a focus on its pathophysiology and promising approaches to mitigate its impact on clinical outcomes.

RECENT FINDINGS

Quadriceps dysfunction (QD) associated with knee joint preservation surgery results from a complex interplay of signaling, related to changes within the joint and from those involving the overlying muscular envelope. Despite intensive rehabilitation regimens, QD may persist for many months postoperatively and negatively impact clinical outcomes associated with various surgical procedures. These facts underscore the need for continued investigation into the potential detrimental effects of regional anesthetic and intraoperative tourniquet use on postoperative quadriceps function, with an outward focus on innovation within the field of postoperative rehabilitation. Neuromuscular stimulation, nutritional supplementation, cryotherapy, blood flow restriction (BFR), and open-chain exercises are all potential additions to postoperative regimens. There is compelling literature to suggest that these modalities are efficacious and may diminish the magnitude and duration of postoperative QD. A clear understanding of QD, with respect to its pathophysiology, should guide perioperative treatment and rehabilitation strategies and influence ongoing rehabilitation-based research and innovation. Moreover, clinicians must appreciate the magnitude of QD's effect on diminished clinical outcomes, risk for re-injury and patients' ability (or inability) to return to pre-injury level of activity following knee joint preservation procedures.

Quadriceps Electromyographic Activity in Closed and Open Kinetic-Chain Exercises with Hip-Adductor Co-Contraction in Sedentary Women

BACKGROUND

Different closed and open kinetic-chain exercises with hip-adductor co-contraction have different effects on quadriceps activity. The aim of this study was to investigate the difference in quadriceps activity during the squat (SQ) and knee extension (KE) and straight leg raise (SLR) exercises with and without hip adduction in sedentary women.

METHODS

Twenty-eight sedentary women aged 44.5 ± 8.5 years were recruited. They performed three exercises with and without hip adduction. Surface electromyography (sEMG) activity was measured on the rectus femoris (RF), vastus medialis oblique (VMO) and vastus lateralis (VL) muscles. The levels of sEMG activities of the three muscles were compared among the six exercises using a repeated-measures ANOVA.

RESULTS

The findings showed that RF activity was lowest during the SQ alone and highest during the SLR exercise (p < 0.05 to 0.001). The VMO activity was significantly greater in the SQH than in the five types of exercises (p < 0.05 to 0.001), which led to a significant VMO/VL ratio as well. VL activity increased while the squat with hip adduction and knee extension with hip adduction exercise compared with SQ alone.

CONCLUSION

This study indicates that a closed-chain squat with hip co-contraction can produce the VMO and VMO/VL ratio activity, while an open chain of SLR better activates the RF activity. The findings support the understanding of quadriceps activity in different exercises to be an alternative home-based exercise for physical therapy in women facing muscle weakness.

Beyond Distance: A Simple Qualitative Assessment of the Single-Leg Hop Test in Return-to-Play Testing

BACKGROUND

Limb symmetry index in the single-leg hop (SLH) test has been questioned for its low predictive value in identifying secondary anterior cruciate ligament (ACL) injury. The purpose of this study was to describe a qualitative 2-dimensional (2D) scoring system for the assessment of the SLH test and associate it with the vertical ground-reaction forces (vGRF) and sagittal plane biomechanics evaluated through gold standard 3D motion analysis.

HYPOTHESIS

Stiff landings would be associated with low 2D scores.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Thirty-four competitive football (soccer) players (age 22.8 ± 4.1 years, 16 women) were enrolled. Each athlete performed a series of SLH tests. Three-dimensional motion analysis was recorded using 10 stereophotogrammetric cameras, a force platform, and 3 high-speed cameras. The 2D qualitative assessment was performed through a scoring system based on the video-analysis of sagittal plane joint kinematics. A score of 0/2 (inadequate), 1/2 (partially adequate), or 2/2 (adequate) was attributed to the movement, based on objective measurements. The vGRF was extracted from the force platform and grouped according to the results of the 2D evaluation.

RESULTS

Significantly higher vGRF (stiffer landing) was found for athletes obtaining a 0/2 score compared with those obtaining a 2/2 score (up to 0.8 body weight higher, P < 0.01). A significant negative rank correlation was found between the vGRF and the total score (ρ = -0.17, P = 0.03).

CONCLUSION

The qualitative scoring system effectively identified stiff landings in the SLH for distance test.

CLINICAL RELEVANCE

The qualitative scoring system could be a user-friendly standardized method to assess athletes' movement quality in return to sport clearance decision after ACL injury.

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.

Short-term isokinetic and isometric strength outcomes after anterior cruciate ligament reconstruction in adolescents

OBJECTIVES

To examine differences in knee strength outcomes after ACL reconstruction according to quadriceps tendon (QT) or hamstring tendon (HT) autograft in adolescents.

DESIGN

Retrospective cohort.

METHODS

Surgical and clinical outcome data were collected. Analyses were conducted separately for female and male cohorts and grouped by graft type (HT or QT). A Mann-Whitney U test of independent samples was used to examine group differences according to graft type.

RESULTS

107 females (age = 15.6 ± 1.5 years) and 94 males (age = 15.7 ± 1.5 years) were included. Mean time since surgery ranged from 7.2 to 7.9 months. Those with a QT autograft had decreased normalized isokinetic quadriceps peak torque on the involved limb compared to the HT group (p < 0.01, ES = 0.71-0.89). Normalized isometric hamstring peak torque was decreased for those with HT autograft in the female cohort (p = 0.02, ES = 0.57).

CONCLUSION

Normalized isokinetic quadriceps peak torque was reduced by 18-20% on the involved limb in those with a QT autograft. Normalized isometric hamstring peak torque was decreased by 13% for those with HT autograft in the female cohort. Method of strength testing may be an important consideration to fully appreciate strength deficits after ACL reconstruction according to graft type.

Feasibility, correlates, and validity of the one-leg sit-to-stand test in individuals following anterior cruciate ligament reconstruction

OBJECTIVE

Regular quadriceps strength assessment is important following anterior cruciate ligament reconstruction (ACLR). The one-leg sit-to-stand (OLSTS) test potentially overcomes the barrier of accessibility to specialised testing equipment. However, feasibility and validity testing of OLSTS is lacking in the ACLR population. This study aims to examine the feasibility, correlates, and predictive validity of OLSTS with self-reported running and jumping difficulty in individuals post-ACLR.

DESIGN

Retrospective longitudinal study.

METHODS

20 patients with primary unilateral ACLR were tested at 6-months and 1-year post-ACLR. Feasibility was assessed by the number of patients who had safely performed OLSTS at both timepoints. Cross-sectional gender-adjusted Spearman correlations of OLSTS with quadriceps strength, physical impairments, and psychological variables were measured at 6-months. Predictive validity was assessed via ordinal regression, quantifying the associations of OLSTS with self-reported running and jumping difficulty across time-points.

RESULTS

All patients understood the instructions to and were able to self-administer the OLSTS test safely. OLSTS is a valid measure of quadriceps strength (gender-adjusted Spearman's ρ = 0.53, P = 0.02). Knee pain (ρ = 0.44, P = 0.046) and readiness to return-to-sport (ρ = 0.55, P = 0.02) were additional correlates. Greater OLSTS performance was associated with greater odds of better self-reported running and jumping function (interquartile-range ORs, 12.0 [95% CI: 3.6-45] and 18.5 [95% CI: 5-67], respectively).

CONCLUSION

OLSTS is a feasible and valid test of quadriceps strength, demonstrating predictive validity with self-reported running and jumping post-ACLR. OLSTS potentially allows independent tracking of ACLR rehabilitation progress at home - an increasingly urgent necessity in the face of a global pandemic.

Isokinetic torque analysis demonstrates deficits in knee flexor and extensor torque in patients at 9-12 months after anterior cruciate ligament reconstruction, despite peak torque symmetry

BACKGROUND

Lower limb strength asymmetry is associated with re-injury after anterior cruciate ligament reconstruction (ACLR). This study investigated limb symmetry indices (LSIs) during isokinetic knee extensor and flexor assessment after ACLR.

METHODS

Overall, 25 patients underwent isokinetic knee extensor and flexor strength assessment, 9-12 months after ACLR with a semitendinosus autograft. While patients were included if they presented with peak knee extensor (PKET) and flexor (PKFT) torque LSIs ≥ 90%, LSIs were calculated at designated points throughout the isokinetic torque range of motion, including: 15°, 30°, 45°, 60° and 75° (from 90° of knee flexion) during PKET and 15°, 30°, 45°, 60° and 75° (from full knee extension) during PKFT. T-tests investigated limb differences for PKET and PKFT, as well as at the final 75° assessment point during knee extension and flexion, between: (1) males and females, (2) those that did, or did not, undergo meniscal surgery, and (3) those undergoing ACLR on their dominant or non-dominant limb.

RESULTS

Significant differences between limbs were observed for PKET at 15° (p = 0.040) and 75° (p = 0.002), and for PKFT at 60° (p = 0.001) and 75° (p < 0.0001). No comparative differences (p > 0.05) were seen based on gender, meniscal surgery or whether ACLR was on the dominant or non-dominant limb.

CONCLUSION

Despite 100% of patients demonstrating PKET and PKFT LSIs ≥ 90%, LSI differences existed at designated points throughout the knee extensor and flexor torque range of motion. Analysis of torques throughout full range should be considered in future studies, as comparison of isolated peak measures miss strength deficits.

Current perspectives and clinical practice of physiotherapists on assessment, rehabilitation, and return to sport criteria after anterior cruciate ligament injury and reconstruction. An online survey of 538 physiotherapists

OBJECTIVES

To evaluate the perspectives and clinical practice of physiotherapists regarding rehabilitation after anterior cruciate ligament reconstruction (ACLR).

DESIGN

Online survey.

SETTING

Survey platform.

PARTICIPANTS

Greek physiotherapists.

OUTCOME MEASURES

The survey consisted of 7 sections: participant demographics, importance of ACLR rehabilitation, clinical measurements, practice, criteria to progress rehabilitation, return to running and return to sport.

RESULTS

Significant variability in measures and criteria used for clinical decision-making were found including: limb symmetry in strength and function, knee range of motion and effusion, progression, and return to sport criteria. The majority of the practitioners (28.3%) extrapolate knee strength from hop capacity. Return to running ranged from 3 to 5 months post-operatively reflecting that this was tied to physical capacities, not time from surgery. 70.0% of the Greek physiotherapists would allow return to sport ≤9 months after ACLR. Agreement was found in using: physical measures, function, and dynamic stability in ACLR rehabilitation, but the mode and interpretation varied substantially. Less than 29.0% of the physiotherapists reported using patient-reported outcome measures in their decision-making.

CONCLUSION

Current ACLR rehabilitation practices in Greece are largely not aligned with the contemporary scientific evidence and guidelines.

Is resistance training intensity adequately prescribed to meet the demands of returning to sport following anterior cruciate ligament repair? A systematic review

Objective

To identify, critique and synthesise the research findings that evaluate the use of resistance training (RT) programmes on return to sport outcome measures for people following ACL repair (ACLR).

Design and data sources

This systematic review included a comprehensive search of electronic databases (EBSCO health databases (CINAHL, MEDLINE, SPORTDiscus), Scopus and Pedro) performed in June 2020 and was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Studies were appraised using the Downs and Black checklist.

Eligibility criteria

Randomised and non-randomised controlled trials, longitudinal cohort studies and case series were considered for inclusion where an adequate description of the RT intervention was provided as a part of the study's ACLR rehabilitation protocol. Articles that did not include outcome measures related to return to sport criteria were excluded.

Results

Eleven articles met the inclusion criteria and were subjected to appraisal and data extraction. Study quality ranged from poor to excellent. RT intensity varied considerably among studies (between 5% and >80% of one repetition maximum). Only one identified study specifically investigated the effect of a low-intensity versus high-intensity RT protocol. The majority of studies reported participant outcomes that would not meet commonly used return to sport criteria.

Conclusion

There appears to be considerable variation in the intensity of RT prescribed in research for people following ACLR. Furthermore, in most of the identified studies, RT protocols promoted muscle endurance and hypertrophy without progressing to strength or power-based RT. The findings of this review provide insight into potential factors limiting returning to sport and contributing to reinjury for people following ACLR.

Rehabilitation strategies of Flemish physical therapists before and after anterior cruciate ligament reconstruction: An online survey

OBJECTIVES

The primary objective of the study was to investigate rehabilitation strategies of Flemish physical therapists before and after anterior cruciate ligament (ACL) reconstruction. Secondly, we aimed to investigate physical therapists' preferences on continuing education and evaluate their self-rated confidence and competence when treating patients before and after ACL reconstruction.

DESIGN

Survey-based study.

SETTING

Online survey platform.

PARTICIPANTS

Flemish physical therapists (n = 283).

MAIN OUTCOME MEASURES

The online survey consisted of a combination of 40 open- and closed-ended questions, divided across 5 sections: (1) participant demographics and clinical practice information, (2) patient population information, (3) continued education practices, (4) rehabilitation strategies, and (5) physical therapist self-rated confidence and competence to treat patients with ACL reconstruction.

RESULTS

A wide variability in rehabilitation strategies were found across the whole ACL rehabilitation continuum, which were in general not in line with best available evidence. Nevertheless, the overall self-rated confidence and competence of physical therapists treating patients before and after ACL reconstruction were high.

CONCLUSION

Our findings indicate a need to improve rehabilitation practices before and after ACL reconstruction. Advanced research dissemination and implementation are required to achieve better rehabilitation outcomes.