Symmetry Index Research Articles

Single Leg Hop Performance After Anterior Cruciate Ligament Reconstruction: Ready for Landing but Cleared for Take-Off?

While the landing phases of the single-leg hop for distance (SLHD) are commonly assessed, limited work reflects how the take-off phase influences hop performance in patients with anterior cruciate ligament reconstruction (ACLR). To compare trunk and lower extremity biomechanics between individuals with ACLR and matched uninjured controls during take-off of the SLHD. Cross-sectional study design. Laboratory setting. 16 individuals with ACLR and 18 uninjured controls. Normalized quadriceps isokinetic torque, hop distance, and respective limb symmetry indices (LSI) were collected for each participant. Sagittal and frontal kinematics and kinetics of the trunk, hip, knee, and ankle, as well as vertical and horizontal ground reaction forces (GRF) were recorded for loading and propulsion of the take-off phase of the SLHD. Those with ACLR had weaker quadriceps peak torque in the involved limb (p=0.001) and greater strength asymmetry (p<0.001) compared to controls. Normalized hop distance was not statistically different between limbs or between groups (p>0.05) and hop distance symmetry was not different between groups (p>0.05). During loading, the involved limb demonstrated lesser knee flexion angles (p=0.030) and knee power (p=0.007) compared to the uninvolved limb, and lesser knee extension moments compared to the uninvolved limb (p=0.001) and controls (p=0.005). During propulsion, the involved limb demonstrated lesser knee extension moment (p=0.027), knee power (p=0.010), knee (p=0.032) and ankle work (p=0.032), anterior- posterior GRF (p=0.047), and greater knee (p=0.016) abduction excursions compared to the uninvolved limb. Between-limb differences in SLHD take-off suggest a knee underloading strategy in the involved limb. These results provide further evidence that distance covered during SLHD assessment can overestimate function and fail to identify compensatory biomechanical strategies.

Cyclogram-based evaluation of inter-limb gait symmetry in Prader-Willi Syndrome

BackgroundPrader-Willi syndrome (PWS) is characterized by a complex clinical condition, whose typical features lead to impaired motor and functional skills. To date, limited data is available as regards symmetry of gait in PWS. Research questionThe aim of this study was to characterize lower-limb asymmetry during gait in a group of Prader-Willi Syndrome (PWS) individuals by using the synchronized cyclograms and to compare it with those of two different control groups, a normal-weight group and an obese group. MethodsA total of 18 PWS, 30 normal weight (NW) and 28 obese individuals (OG) matched for age, sex and height were assessed via 3D gait analysis. Gait spatio-temporal parameters were computed together with angle-angle diagrams, characterized in terms of their geometric features (i.e. area, orientation, and trend symmetry index). ResultsIndividuals with PWS exhibit reduced speed, stride length and cadence and increased duration of both stance and double support phase than the other groups. OG was characterized by the same pattern when compared to NW. With respect to inter-limb symmetry, individuals with PWS exhibited significantly larger cyclogram areas at hip joint with respect to the other two groups (203.32 degrees2 vs. 130.73 degrees2 vs. 111.59 degrees2) and significantly higher orientation angle (4.17° vs. 2.11° vs. 1.22°) and Trend Symmetry (3.72 vs. 2.02 vs. 1.21) with respect to the other two groups at knee joint; no differences were found at ankle joint. Both individuals with PWS and those of OG exhibited reduced ROM at knee and ankle joints with respect with normal weight, but no statistically significant differences were observed between PWS and OG. SignificanceThe obtained results may provide novel and useful insights to understand better the impairments in motor control associated with this pathological state, supporting clinics in the identification of the best rehabilitation program for this rare pathological state, aimed to improve stability and motor control.

Addition of anterolateral ligament reconstruction to primary anterior cruciate ligament reconstruction could benefit recovery of functional outcomes

This study aimed to compare functional outcomes sequentially up to 1 year after combined anterior cruciate ligament reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) and isolated ACLR. Fifty patients who underwent ACLR with versus without ALLR were analyzed at four different time points (preoperatively and 3, 6, and 12 months postoperatively). For the functional outcomes, muscle strength and acceleration time (AT) were measured using an isokinetic dynamometer. Proprioception was evaluated using joint position sense and dynamic postural stability. Patient-reported outcomes were measured using the Tampa Scale for Kinesiophobia (TSK-11) scores. Functional performance was assessed using single-leg hop distance (SLHD) and Limb Symmetry Index. In the operated knees, quadriceps (at 6 months postoperatively, p = 0.003) and hamstring (at 6 and 12 months postoperatively, p < 0.001) strength were significantly higher in the combined ACLR and ALLR group than the isolated ACLR group. The TSK-11 (at 6 and 12 months postoperatively, p < 0.001) was significantly lower in the combined ACLR and ALLR group than the isolated ACLR group. SLHD was significantly higher in the combined ACLR and ALLR group than the isolated ACLR group (at 6 months, p = 0.022 and at 12 months, p = 0.024). The addition of ALLR to primary ACLR yielded better muscle performance, fear of movement, and functional performance than isolated ACLR.

Estimating the Reliability and Validity of the Quadrant Hop Test in the Assessment of the Functional Stability of the Knee.

Background Many sporting activities demand multidirectional skills and movements, emphasizing the importance of various fitness components such as functional stability, strength, power, endurance, and range of motion. These aspects must be thoroughly assessed before athletes can return to sports safely following an injury. Although the single-leg hop test (SHT) is widely used as the gold standard for evaluating joint stability, it has limitations in assessing multidirectional movements. Therefore, further research is necessary to explore whether increasing the dynamicity of the hop test in different directions enhances its sensitivity in assessing knee joint stability across all four directions. The objective of this study was to investigate the applicability of a new functional assessment tool, the quadrant hop test (QHT), for evaluating lower limb functional stability. Methodology One hundred nineteen amateur sportsmen who are in the age group of 18-25 years with a limb symmetry index of the lower limb calculated through SHT of >80% were included. All the participants performed the SHT, a triple hop test (THT), a crossover hop test (CHT), and the QHT on two different days, with two investigators assessing the QHT on different days and then recording the measurements of Hop distance. Results The mean difference between SHT, THT, and CHT with QHT was 4.59%, with a moderate correlation between all the hop tests. The Cronbach's alpha revealed good intra-rater (0.917) and inter-rater reliability (0.912) of the QHT. Conclusion The QHT proves to be a reliable and valid measure for assessing the functional stability of the lower limb and is 4.59% more sensitive than SHT, THT, and CHT in assessing knee stability and in return to sports criteria.

Changes in Young Swimmers' In-Water Force, Performance, Kinematics, and Anthropometrics over a Full Competitive Season.

The aim of the present study was to analyze changes in young swimmers' in-water force, performance, kinematics, and anthropometrics during one full competitive season. Twenty-five swimmers (11 girls and 14 boys, 12.04 ± 0.16 years) were assessed over four distinct time points throughout a competitive season. The in-water force of both hands (D, dominant; ND, non-dominant) was retrieved during two bouts of 25 m front crawl allowing the estimation of the symmetry index. The velocity (v25) was calculated from the time to complete the 25 m and considered the performance outcome, while the stroke rate, stroke length, and the stroke index were used as kinematic variables. For anthropometric variables, body mass, stature, arm span and the hand surface area were measured. The in-water force (16-24%) and performance (8%) improved over the competitive season with significant changes in the first macrocycle. The stroke index was the only kinematic variable that changed between M1 and M4 (12.7%), accompanied by a higher asymmetric motion later in the season. A time effect was found in the stature (p < 0.001, ηp 2 = 0.71), the arm span (p < 0.001, ηp 2 = 0.79), and the hand surface area (D = p < 0.001, ηp 2 = 0.63; ND = p < 0.001, ηp 2 = 0.666). Swimming performance showed associations with in-water force, stroke efficiency and anthropometric features in all time points of the season. Thus, the natural anthropometric growth experienced over the season may translate into a more efficient swimming pattern with greater in-water forces that can enhance performance.

Psychological Factors Are Related to Neuromuscular Asymmetries After Anterior Cruciate Ligament Reconstruction.

After an anterior cruciate ligament reconstruction (ACLR), only 47% of military members return to full duty, possibly due to persistent neuromuscular asymmetries. Psychological factors may also contribute to reduced return to duty in military members. Psychological factors and time since surgery would be associated negatively with neuromuscular asymmetries, asymmetries would be greater in cadets postsurgery when compared with healthy controls, and asymmetries would be greater at earlier timepoints after ACLR. Case control. Level 4. This study examined the relationship between psychological factors and time since surgery with neuromuscular asymmetry, compared neuromuscular asymmetries between cadets with and without a history of ACLR, and explored differences in neuromuscular asymmetries at different timepoints in cadets with a history of ACLR. A total of 37 cadets post-ACLR (18.3 ± 9 months) and 28 controls participated. Psychological factors were assessed using the Tampa Scale of Kinesiophobia and Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI). Participants performed a drop-jump landing, joint positioning sense (JPS), and isometric quadriceps strength testing. Peak vertical ground-reaction forces (vGRF), absolute angle of replication, peak quadriceps torque, rate of torque development (RTD), and RTD time torque interval 200 ms (TTI200) were analyzed. The ACL-RSI score was significantly related to limb symmetry index (LSI) peak quadriceps torque (r = 0.617, P < 0.01), LSI RTD (r = 0.367, P = 0.05), and LSI TTI200 (r = 0.0489, P < 0.01), but not time since surgery, JPS, or LSI peak vGRF. Cadets with a history of ACLR had significantly lesser ACL-RSI scores and greater asymmetries compared with controls. Reduced psychological readiness was associated with increased neuromuscular asymmetries after ACLR. Clinicians should assess psychological readiness during rehabilitation after ACLR.

Effect of tibial plateau angle < 5° on ground reaction forces in dogs treated with tibial plateau leveling osteotomy for cranial cruciate ligament rupture up to 6 months postoperatively

Tibial plateau leveling osteotomy (TPLO) has been commonly performed in dogs with cranial cruciate ligament disease (CCLD) since the introduction by Slocum and Slocum (1993). To reduce cranial tibial thrust the TPLO technique aims for a postoperative tibial plateau angle (TPA) of 5–6.5°. In recent years studies have shown that a postoperative TPA below 5° could be beneficial regarding stifle stability or meniscal load. Dogs with CCLD that were treated with TPLO, were examined preoperatively, six weeks, three and six months postoperatively with gait analysis and grouped according to their postoperative TPA. The aims of study was (1) to evaluate if dogs with a postoperative TPA below 5° would have a faster limb function recovery up to six months postoperatively as measured objectively with ground reaction forces (GRFs) and (2) to determine whether the postoperative TPA correlates with the outcome measurements. Dogs with TPA <5° showed no faster limb function recovery postoperatively up to six months as measured with peak vertical force (PVF) or vertical impulse (VI) (p > 0.05). No correlation for the postoperative TPA <5° on GRFs was demonstrated. But the postoperative TPA showed a significant correlation with the symmetry indices of PVF (SIPVF) and VI (SIVI) for all dogs (>5° and <5° TPA together), indicating that with lower postoperative TPA dogs had a more symmetrical gait in hindlimbs SIPVF (r = 0.144, p < 0.05) and SIVI (r = 0.189, p < 0.01). The study indicates that a lower postoperative TPA could be beneficial regarding hindlimb symmetry indices of GRFs.

PLATELET-RICH PLASMA FOR ACUTE ACHILLES TENDON RUPTURE: RESULTS OF THE PATH-2 STUDY, A DOUBLE-BLIND MULTICENTRE RANDOMIZED PLACEBO-CONTROLLED TRIAL

BackgroundDisability and slow return to sport and work after tendon rupture are major challenges. Platelet Rich Plasma (PRP) is an autologous supraphysiological concentration of platelets from whole blood that has demonstrated positive cellular and physiological effects on healing in laboratory conditions but evidence from adequately powered robust clinical trials is lacking. We aimed to determine the clinical efficacy of PRP for treatment of acute Achilles tendon rupture.MethodsIn a placebo-controlled, participant- and assessor-blinded, trial at 19 NHS hospitals we randomly assigned 230 adults starting acute Achilles rupture non-surgical management to PRP injection or dry-needle insertion (placebo) to the rupture gap under local anaesthetic. Patients with confounding or contraindicated concurrent medical conditions were excluded. The primary outcome was muscle-tendon function, assessed by the limb symmetry index (LSI, uninjured limb/injured limb × 100, higher scores better) of the work (Joules) performed during the heel-rise endurance test at 24 weeks. Secondary outcomes were: Achilles Tendon Rupture Score (ATRS, 0–100, higher scores better), quality of life (SF-12), pain, and goal attainment. Trial registration: ISRCTN54992179ResultsParticipants were aged mean 46 years and 57 (25%) were female. 103/114 (90%) of the PRP group and all (n=116) in the placebo group received allocated treatment. At 24 weeks, mean LSI was 34.4 for the PRP group and 38.8 for placebo (adjusted mean difference −4.4 95% CI −11.2 to 2.5, n=201) and ATRS was mean 65.2 PRP vs 65.8 (adjusted mean difference −0.6, 95% CI −4.9 to 3.7, n=224). There were no differences between groups in the other secondary outcomes.ConclusionWe found no evidence of PRP efficacy for improving muscle-tendon function or patient-reported recovery after acute Achilles tendon rupture. Our findings challenge the increasing global use of PRP for acute tendon injury and indicate that robust evaluations are required in other applications.

Are Functional Performance Test Scores Better When Compared to Baseline or Contralateral Limb Scores Following LE Injury in Adolescent Athletes?

Functional performance tests (FPT) have been used with athletes following an injury to determine readiness to return-to-play (RTP), usually using limb symmetry indices to the contralateral limb or a baseline score. There is not a consensus as to which criterion scores are best compared. This study aimed to compare common functional performance test scores from injured athletes at the time of release to RTP to both preseason baseline scores and to the contralateral limb. It was hypothesized that using baseline scores for comparison would be more responsive to residual deficits following injury than using the contralateral limb. Prospective longitudinal cohort study. High school athletes (n=395) from all varsity sports completed a battery of FPTs including the Y-Balance Test (YBT), single limb hop tests and T-Test for agility (TT) during their preseason to establish baseline data. Injured athletes (n=19) were re-tested using all FTP's again at the time of RTP. Paired t-tests were used to detect if significant (p\<0.05) residual deficits were present at time of RTP when compared to baseline and to contralateral scores on FPTs. Differences in YBT scores were found in the anterior direction only (p=0.021) when comparing RTP to preseason, but there were no differences when compared to RTP data for the contralateral limb. Differences were detected with the single leg hop test (p = 0.001) when comparing the RTP to preseason and were also detected in both the single leg hop (p= 0.001) and triple hop (p=0.018) when compared to the contralateral limb. Differences in TT scores were detected when comparing RTP to preseason for cutting first with both the unaffected (p = 0.019) and affected (p = 0.014) limbs. The YBT in the anterior direction and the TT are better able to detect residual deficits when comparing RTP to preseason scores. Hop tests are better able to detect deficits when compared to the contralateral limb. These results could make preseason testing more efficient when creating a reference for determining RTP readiness following lower extremity injury.

PATIENTS WITH FEMOROACETABULAR IMPINGEMENT SYNDROME OBTAIN SIGNIFICANT AND SUSTAINED IMPROVEMENT FOLLOWING A COMBINED HIP INJECTION AND REHABILITATION PROGRAM

INTRODUCTION Initial treatment recommendations for symptomatic femoroacetabular impingement syndrome include non-surgical therapies such as injections and rehabilitation. However, many patients undergo isolated injections or a rudimentary exercise regime. This study investigated the benefit of a combined intra-articular hip injection and structured exercise rehabilitation program in patients with FAIS. METHODS Participants were recruited and underwent a guided intra-articular injection of corticosteroid and local anaesthetic, followed by a 12-week rehabilitation program. Patients were assessed pre-and post-injection(8 weeks, 4, 6, 12 and 24 months) via patient-reported outcome measures including the 33-item International Hip Outcome Tool and Hip Outcome score. Hip ROM and peak isometric hip strength in all planes were assessed, along with single-limb hop capacity. Limb Symmetry Indices were calculated. The percentage of patients transitioning toward surgery over the period was evaluated. RESULTS A total of 44 patients underwent the injection and completed the initial 8-week rehabilitation component. A significant improvement (p&amp;lt;0.05) in all PROMs was observed, with 93% of patients satisfied. A significant increase (p&amp;lt;0.05) in all active hip ROM and isometric strength measures was observed, sustained over the 24-month period. Bilateral improvements in hop capacity were observed, with all hop test LSIs significantly improving (p&amp;lt;0.05). Overall, 14 patients (32%) progressed toward surgical intervention over the 24-month post-injection period. These patients reported significantly worse (p&amp;lt;0.05) PROMs pre-surgery and more pain within the first 4 weeks post-injection. CONCLUSION This is the first study seeking to implement and comprehensively assess a best-practice, multimodal non-operative program consisting of an intra-articular injection and a structured exercise program. Most patients with symptomatic FAIS demonstrated significant improvement in symptoms.

AN INVESTIGATION OF SEX-BASED DIFFERENCES IN PHYSICAL AND PSYCHOLOGICAL RECOVERY, AND RETURN TO SPORT, FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

INTRODUCTION &amp; AIMS Despite the increasing rate of anterior cruciate ligament (ACL) tears and surgical reconstruction (ACLR), little is known about the post-operative recovery in males versus females. Understanding differences in the recovery between sexes will assist in better tailoring rehabilitation, return to sport (RTS) and counselling pathways. This study investigated sex-based differences in the physical and psychological recovery of both females and males after ACLR. METHODS This study recruited 104 patients (49 females, 55 males) undergoing ACLR. Patients were assessed pre-operatively and at 6, 12 and 24 months post-surgery, via patient-reported outcome measures (PROMs) including the International Knee Documentation Committee (IKDC) form, the Tegner Activity Scale (TAS) and the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) score. Patients embarked on an assessment of peak isokinetic knee extensor (PKET) and flexor (PKFT) torque and a 4-hop performance battery. Limb Symmetry Indices (LSIs) were calculated. The incidence of RTS was investigated. RESULTS All PROMs significantly improved (p&amp;lt;0.05), though females reported significantly lower ACL-RSI (p=0.002) and IKDC (p=0.007) scores. While no sex-based differences were observed in hop test LSIs, males demonstrated significantly higher mean LSIs for PKET at 6 (p=0.037) and 24 (0.047) months, and PKFT at 6 (p=0.007) and 12 (p=0.002) months. At 24-months post-surgery, a significantly greater (p=0.030) percentage of male patients had returned to pivoting sports. CONCLUSION This study demonstrates the disparity between sexes in physical and psychological recovery, as well as RTS status, in community-level patients undergoing ACLR. The development and implementation of enhanced post-operative patient-centered care may be warranted tailored to sex, encompassing rehabilitation, education, and counseling after ACLR to promote increased engagement in rehabilitation.

A RANDOMIZED CONTROLLED TRIAL EVALUATING AN ACCELERATED WEIGHT-BEARING REHABILITATION PATHWAY AFTER MATRIX-INDUCED AUTOLOGOUS CHONDROCYTE IMPLANTATION FOR SYMPTOMATIC KNEE CARTILAGE DEFECTS

INTRODUCTION &amp; AIMS Matrix-induced autologous chondrocyte implantation (MACI) has demonstrated encouraging outcomes in treating symptomatic knee cartilage lesions which, if untreated, can progress toward early osteoarthritis. Rehabilitation is imperative to optimize outcome, though has been traditionally conservative. This study investigated the long-term outcomes of an accelerated return to full weight bearing (WB) after MACI. METHODS This prospective randomized controlled trial (RCT) allocated 35 patients (37 knees) to a 6-week (n=18) or 8-week (n=19) return to full WB after MACI. Patients were evaluated pre-operatively and at 1, 2, 5 and ≥10 years, via patient-reported outcome measures (PROMs) including the Knee Osteoarthritis Outcome Score (KOOS). Single limb hop capacity and peak knee extensor and flexor torque were assessed, with limb symmetry indices (LSIs) calculated. Magnetic resonance imaging (MRI) evaluated repair tissue, while a validated MRI composite graft score was calculated. RESULTS While the 6-week WB group reported significantly better 1-year KOOS Quality of Life scores, no other differences (p&amp;gt;0.05) in PROMs existed. The peak knee extensor torque LSI significantly improved (p&amp;lt;0.0001) over time, with mean LSIs of 100.8 (6-week) and 99.1 (8-week) at ≥10 years. No group differences (p&amp;gt;0.05) were observed in hop LSIs. A non-significant decline (p&amp;gt;0.05) was observed for the MRI composite score from 1-year to final ≥10-year review and, apart from a significant group effect (p=0.028) for graft tissue intensity in favor of the 6-week group suggesting repair tissue more reflective of native cartilage, no other MRI-based differences (p&amp;gt;0.05) existed. At ≥10-years, no grafts on MRI had failed, though 3 patients (6-week n=1, 8-week n=2) had progressed toward knee arthroplasty. CONCLUSION The 6-week accelerated rehabilitation program provided comparable clinical and MRI-based outcomes beyond 10 years post-surgery, without jeopardizing the graft.

Outcomes of Blood Flow Restriction Training After ACL Reconstruction in NCAA Division I Athletes.

Blood flow restriction training (BFRT) is a safe and potentially effective adjunctive therapeutic modality for postoperative rehabilitation related to various knee pathologies. However, there is a paucity of literature surrounding BFRT in high-performance athletes after anterior cruciate ligament reconstruction (ACLR). To (1) compare the overall time to return to sports (RTS) in a cohort of National Collegiate Athletic Association (NCAA) Division I athletes who underwent a standardized rehabilitation program either with or without BFRT after ACLR and (2) identify a postoperative time interval for which BFRT has the maximum therapeutic benefit. Cohort study; Level of evidence, 3. A total of 55 student-athletes who underwent ACLR between 2000 and 2023 while participating in NCAA Division I sports at a single institution were included in this study. Athletes were allocated to 1 of 2 groups based on whether they participated in a standardized postoperative rehabilitation program augmented with BFRT (BFRT group; n = 22) or completed the standardized protocol alone (non-BFRT group [control]; n = 33). Our primary outcome measure was time to RTS. The secondary outcome measure was handheld dynamometry quadriceps strength testing at various postoperative time points, converted to a limb symmetry index (LSI). Quadriceps strength was not tested between the BFRT and non-BFRT groups because of the limited amount of data on the control group. The mean age at the date of surgery was 18.59 ± 1.10 years for the BFRT group and 19.45 ± 1.30 years for the non-BFRT group (P = .011), and the mean RTS time was 409 ± 134 days from surgery for the BFRT group and 332 ± 100 days for the non-BFRT cohort (P = .047). For the BFRT group, the mean quadriceps strength LSI increased by 0.67% (95% CI, 0.53%-0.81%) for every week of rehabilitation, and there was a significantly positive rate of change in quadriceps strength in weeks 13-16 compared with weeks 9-12 (ΔLSI, 8.22%; P < .001). In elite NCAA Division I athletes, a statistically significant delay was observed in RTS with BFRT compared with standardized physical therapy alone after undergoing ACLR. There also appeared to be an early window during the rehabilitation period where BFRT had a beneficial impact on quadriceps strength.

LOWER LIMB PERFORMANCE AND KINETIC ASYMMETRIES IN PATIENTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

INTRODUCTION AND AIM Analyses of functional performance and movement strategies at key clinical milestones during rehabilitation are critical to guide rehabilitation and return-to-sport (RTS) decisions post-anterior cruciate ligament reconstruction (ACLR). The aim of this study was to evaluate lower limb performance and kinetics during jumping and hopping in patients post-ACLR. METHODS Seventy-one patients (39 males, 32 females; mean age 27.0 years; height 1.74m; weight 76.5kg) underwent lower limb evaluation at 6.1 and 10-months post-ACLR. Patient-reported outcomes (IKDC-2000, ACL-RSI) were collected at both time points. Ground reaction forces during bilateral and unilateral countermovement jumps (CMJ) on dual force plates were recorded, alongside unilateral horizontal hops for distance (HHD). Paired sample t-tests examined between-limb differences in eccentric and concentric phases of the bilateral CMJ and jump heights and distances of the unilateral CMJ and HHD, respectively, at both time points. Differences in limb asymmetries between the unilateral CMJ and HHD were also examined. Chi square tests were performed to examine differences in meeting known RTS thresholds (&amp;gt;90% limb symmetry index [LSI]). RESULTS Moderate to large asymmetries were observed for concentric (effect size [ES] = -1.06, P&amp;lt;0.001) eccentric phases (ES = 0.54, p&amp;lt;0.001) during the bilateral CMJ at both time points. Greater limb asymmetry was observed in the unilateral CMJ compared to the HHD at 6-months (ES = -0.52; p≤0.001) and 10-months (ES = -0.56; p≤0.001). Significantly more participants “passed” a horizontal hop test versus a vertical hop test at 6 months (χ2=7.07, p=0.008) and at 10 months (χ2=7.52, p=0.006). CONCLUSION Vertical performance metrics can better identify between-limb asymmetries than HHD and should be included in RTS testing batteries following ACLR. Between-limb deficits in key eccentric and concentric phases of the bilateral CMJ are also apparent at 6- and 10-months after ACLR, suggesting a persistent offloading strategy even at the time of RTS.

A RANDOMIZED CONTROLLED TRIAL INVESTIGATING PATIENT RECOVERY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION UNDERTAKEN WITH A QUADRICEPS VERSUS HAMSTRINGS TENDON AUTOGRAFT

INTRODUCTION &amp; AIMS Anterior cruciate ligament (ACL) tears are common. However, a lack of high-quality evidence exists comparing different graft options in patients undergoing surgical reconstruction (ACLR). This randomized controlled trial (RCT) investigated the course of recovery in patients undergoing ACLR with either a quadriceps (QT) or hamstrings (HT) tendon autograft. METHODS This study randomized 112 patients to one of the two graft reconstruction cohorts (HT=55, QT=57), subsequently undergoing ACLR and a structured rehabilitation program. Patients were assessed pre-surgery and at 6 weeks and 3, 6, 12 and 24 months, with a range of patient-reported outcome measures (PROMs) including the International Knee Documentation Committee form (IKDC) and the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) score. Graft laxity, peak isokinetic knee extensor and flexor strength and a 6-hop performance battery were assessed. Limb Symmetry Indices (LSIs) were calculated. RESULTS All PROMs significantly improved (p&amp;lt;0.0001). Apart from the ACL-RSI score which was significantly better (p&amp;lt;0.05) in the HT group at 3, 6 and 12 months, no other group differences (p&amp;gt;0.05) were observed. No group differences (p=0.407) were observed for knee laxity. While the HT group demonstrated significantly greater (p&amp;lt;0.05) quadriceps strength LSIs at 6 and 12 months, the QT group demonstrated significantly greater (p&amp;lt;0.05) hamstrings strength LSIs at 6, 12 and 24 months. The HT group demonstrated significantly greater (p&amp;lt;0.05) LSIs for the single horizontal (6 months), lateral (6 and 12 months) and medial (6 months) hop tests. CONCLUSION The HT group reported a higher level of psychological readiness to return to sport, while demonstrating greater quadriceps strength (and hop test) LSIs. Greater hamstring strength LSIs were observed for the QT cohort. Longer-term review will continue to evaluate RTS and later-stage re-injury between the two graft constructs.

Anterior-Posterior Center of Pressure Is Associated With Knee Extensor Moment During Landing After Anterior Cruciate Ligament Reconstruction.

A reduced knee extensor moment (KEM) in the involved limb and asymmetry in the KEM during landing tasks are observed after anterior cruciate ligament reconstruction (ACLR). There is limited information about the association of kinetic and kinematic parameters with the KEM during landing after ACLR. This study investigated the association of the anterior-posterior center of pressure (AP-COP) position, vertical ground reaction force (VGRF), and lower limb joint angles with the KEM during landing in female athletes following ACLR. Cross-sectional study. Twenty-two female athletes who underwent ACLR performed a drop vertical jump at 7.9 (1.7)months after surgery. We evaluated the KEM, AP-COP position, VGRF, and sagittal plane hip, knee, and ankle angles using a 3-dimensional motion analysis system with force plates. The peak KEM in the involved limb was significantly smaller than that in the uninvolved limb during landing (1.43 [0.33]N·m/kg/m vs 1.84 [0.41]Nm/kg/m, P = .001). The VGRF in the involved limb was significantly smaller than that in the uninvolved limb (11.9 [2.3]N/kg vs 14.6 [3.5]N/kg, P = .005). The limb symmetry index of the KEM was predicted by that of the VGRF (P < .001, R2 = .621, β = 0.800). The KEM was predicted by the AP-COP position in the involved limb (P = .015, R2 = .227, β = 0.513) and by the VGRF in the uninvolved limb (P = .018, R2 = .213, β = 0.500). No significant correlation was noted between the KEM and the lower limb joint angles. The AP-COP position and VGRF were associated with the KEM during landing. Evaluating the VGRF and AP-COP position, not the lower limb joint angles, may contribute to understanding the KEM during double-leg landing after ACLR in the clinical setting.

A RANDOMIZED CONTROLLED TRIAL INVESTIGATING FUNCTIONAL RECOVERY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING A SINGLE VERSUS DOUBLE TENDON HARVEST

INTRODUCTION &amp; AIMS Anterior cruciate ligament (ACL) tears are common. While surgical reconstruction (ACLR) is commonly advocated and a hamstring autograft is the popular choice, hamstring tendon harvest has been linked to reduced hamstring strength and ongoing donor site pain. While traditional surgical techniques required a harvest of both semitendinosus/gracilis tendons, modern harvesting and fixation methods permit a shorter, broader harvest of semitendinosus only. This study investigated donor site pain, strength and functional recovery in patients undergoing ACLR via a single (ST) versus dual (DT) tendon hamstring harvest. METHODS This prospective randomized controlled trial (RCT) allocated 138 patients to ACLR with one of the two hamstring tendon graft options (ST=71, DT=67) followed by a structured rehabilitation program. Patients were assessed pre-surgery and at 3, 6, and 12 months, with a range of patient-reported outcome measures (PROMs) including a validated donor-site morbidity score. Graft laxity, peak isokinetic knee extensor and flexor strength and a 6-hop performance battery were assessed. Limb Symmetry Indices (LSIs) were calculated. RESULTS All PROMs significantly improved (p&amp;lt;0.0001) and were largely similar between groups (p&amp;gt;0.05), apart from significantly less graft morbidity reported in the ST group (p=0.001). No group differences were observed for knee laxity or LSIs for hop measures (p&amp;gt;0.05), nor the LSIs for peak knee flexor (p=0.113) or extensor (p=0.286) torque. CONCLUSION While the ST ACLR group reported significantly less harvest site morbidity, no other subjective or functional differences were observed in patients undergoing ACLR with either a single or dual hamstring tendon autograft harvest.

No Association Between Injury-Related Fear and Isokinetic Quadriceps Strength in Individuals With a History of Anterior Cruciate Ligament Reconstruction.

Injury-related fear and quadriceps strength are independently associated with secondary anterior cruciate ligament (ACL) injury risk. It is not known whether injury-related fear and quadriceps strength are associated, despite their individual predictive capabilities of secondary ACL injury. The purpose of this study was to examine the association between injury-related fear and quadriceps strength in individuals at least 1year after ACL reconstruction (ACLR). Cross-sectional study. Forty participants between the ages of 18 and 35years at least 1year post unilateral primary ACLR. Participants completed the Tampa Scale of Kinesiophobia-11 (TSK-11) and a standard isokinetic quadriceps strength assessment using the Biodex Isokinetic Dynamometer. Pearson Product-Moment correlations were used to examine the linear association between the TSK-11 scores and peak torque (in nanometers per kilogram) for each limb and between the TSK-11 scores and limb symmetry indices for each limb. Pearson Product-Moment correlation coefficients (r) were interpreted as very high (.90-1.00), high (.70-.90), moderate (.50-.70), low (.30-.50), and no correlation (.00-.30). The average TSK-11 score was 18.2 (5.3), average ACLR peak quadriceps torque was 1.9 (0.50)N·m/kg, average contralateral peak quadriceps torque was 2.3 (0.48)N·m/kg, and average limb symmetry index was 85.3% (12.6%). There was no statistically significant correlation between the TSK-11 and peak quadriceps torque on the ACLR limb (r = .12, P = .46), the TSK-11 and contralateral limb (r = .29, P = .07), or the TSK-11 and limb symmetry index (r = -.18, P = .27). There was no association between kinesiophobia and peak isokinetic quadriceps strength in individuals at least 1year post-ACLR. Both factors, independently, have been shown to influence risk of secondary injury in patients after ACLR.

'Real world' clinical implementation of blood flow restriction therapy does not increase quadriceps strength after quadriceps tendon autograft ACL reconstruction.

To retrospectively compare strength outcomes of individuals undergoing postoperative rehabilitation following quadriceps tendon (QT) autograft anterior cruciate ligament reconstruction (ACLR) with and without blood flow restriction therapy. A retrospective review of consecutive patients undergoing ACLR with QT autograft with a minimum of two quantitative postoperative isometric strength assessments via an electromechanical dynamometer (Biodex) was included. Demographics, surgical variables and strength measurement outcomes were compared between patients undergoing blood flow restriction therapy as part of postoperative rehabilitation versus those who did not. Eighty-one (81) patients met the inclusion criteria. No differences were found in demographic and surgical characteristics between those who received blood flow restriction compared with those who did not. While both groups had improvements in quadriceps peak torque and limb symmetry index (LSI; defined as peak torque of the operative limb divided by the peak torque of the nonoperative limb) over the study period, the blood flow restriction group had significantly lower mean peak torque of the operative limb at first Biodex strength measurement (95.6 vs. 111.2 Nm; p = 0.03). Additionally, the blood flow restriction group had a significantly lower mean LSI than those with no blood flow restriction at the second Biodex measurement timepoint (81% vs. 90%; p = 0.02). No other significant differences were found between the strength outcomes measured. Results of this study show that the 'real world' clinical implementation of blood flow restriction therapy to the postoperative rehabilitation protocol following QT autograft ACLR did not result in an increase in absolute or longitudinal changes in quadriceps strength measurements. A better understanding and standardisation of the use of blood flow restriction therapy in the rehabilitation setting is necessary to delineate the true effects of this modality on strength recovery after QT autograft ACLR. Level III.

Good physical function but reduced quality of life in children 3 years after ACL reconstruction.

To assess children's physical function and subjective knee status 1 and 3 years after anterior cruciate ligament (ACL) reconstruction. It was hypothesised that there was no difference between the operated and normal legs in relation to physical strength and function, that there was <-2 mm side-to-side difference in knee laxity, and that the subjective knee function was better 3 years after ACL reconstruction compared to 1 year after. Children (<16 years of age) who had an ACL reconstruction had follow-up with physical function tests (four hop tests and strength measurement in a power rig [PR]), anterior knee laxity (measured using a Rolimeter) and patient-reported outcome measures (Pedi-International Knee Documentation Committee [IKDC] and Knee injury and Osteoarthritis Outcome Score [KOOS]-Child) 1 and 3 years postoperatively. Changes from 1- to 3-year follow-up were evaluated with a paired t test. Out of 148 ACL reconstructed children, 60 had all measures. The four hop tests and the PR all yielded a Limb Symmetry Index >90% at both follow-ups. There was a significant improvement from 1- to 3-year follow-up in two-hop tests (6 m on time and crossover hop). Side-to-side knee laxity was >2 mm in four children at 1- and 3-year tests. Pedi-IKDC scores increased, and KOOS-Child improved significantly from 1 to 3 years in two of the five domains: 'Sport' and 'Quality of life', but scores were lower than in a cohort of normal children. The children had good objective physical function 1 and 3 years after ACL reconstruction. However, scores from the KOOS-Child sport-specific function and quality of life domains were lower than in normal children. Level II.