Establishing Normal Variances and Expectations for Quadriceps Limb Symmetry Index Benchmarks Based on Time from Surgery After Anterior Cruciate Ligament Reconstruction

The anticipated timeline for muscle strength as well as return to running and sports are some of the most common inquiries by patients undergoing anterior cruciate ligament reconstruction. Despite the popularity of this procedure, the answers to these inquiries are not well described in the literature. The purpose of this study was to evaluate the range of quadriceps strength percentage and function benchmarks at various points after anterior cruciate ligament reconstruction surgery based on sex, age, and graft.

Design

Observational Cohort Study.

Methods

Patients who underwent anterior cruciate ligament reconstruction (ACLR) were evaluated at various points after their surgery with handheld dynamometer assessments. Additional hop and balance testing was performed and patients were evaluated for clearance for running and sport via a physical therapist directed functional movement assessment (FMA). The progression of quadriceps symmetry throughout the postoperative period was examined with multi-level models, estimates of time to reach 70%, 80%, and 90% quadriceps symmetry were obtained from the fitted model.

Results

A total of 164 patients were evaluated. Patients either received bone-tendon-bone (BTB) autograft (n=118) or BTB allograft (n=46) for their ACL graft. Average age was 31.1 years-of-age (SD: 13.6). Males undergoing ACLR using BTB autograft (n=53) were able to achieve 80% quadriceps symmetry earlier than females (n=65) (5.7 months vs 7.1 months), were cleared to return to run sooner (5.6 months vs 6.8 months) and passed an FMA exam earlier (8.5 months vs 10 months). Males undergoing ACLR with allograft (n=13) were able to achieve 80% quadriceps symmetry earlier than females (n=33) (3.9 months vs 5.4 months) and were cleared to run sooner (4.5 months vs 5.8 months).

Conclusion

Patients undergoing BTB autograft obtain 80% quadriceps symmetry at an average of 5.7 months for males and 7.1 months for females. Individuals under the age of 25 obtain their quadriceps symmetry faster and are cleared to return to running faster than individuals over 25. Male sex is associated with decreased amount of time to obtain clearance for running and for full activity. Male sex is associated with decreased amount of time to regain quadriceps symmetry however this was not significant.

Level of Evidence

4 (Case series).

Weaker Quadriceps Muscle Strength With a Quadriceps Tendon Graft Compared With a Patellar or Hamstring Tendon Graft at 7 Months After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Impaired quadriceps muscle strength after anterior cruciate ligament reconstruction (ACLR) is associated with worse clinical outcomes and a risk of reinjuries. Yet, we know little about quadriceps muscle strength in patients reconstructed with a quadriceps tendon (QT) graft, which is increasing in popularity worldwide.

PURPOSE

To describe and compare isokinetic quadriceps strength in patients undergoing ACLR with a QT, hamstring tendon (HT), or bone-patellar tendon-bone (BPTB) autograft.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We included patients with QT grafts (n = 104) and matched them to patients with HT (n = 104) and BPTB (n = 104) grafts based on age, sex, and associated meniscal surgery. Data were collected through clinical strength testing at a mean of 7 ± 1 months postoperatively. Isokinetic strength was measured at 90 deg/s, and quadriceps strength was expressed as the limb symmetry index (LSI) for peak torque, total work, torque at 30° of knee flexion, and time to peak torque.

RESULTS

Patients with QT grafts had the most impaired isokinetic quadriceps strength, with the LSI ranging between 67.5% and 75.1%, followed by those with BPTB grafts (74.4%-81.5%) and HT grafts (84.0%-89.0%). Patients with QT grafts had a significantly lower LSI for all variables compared with patients with HT grafts (mean difference: peak torque: -17.4% [95% CI, -21.7 to -13.2], P < .001; total work: -15.9% [95% CI, -20.6 to -11.1], P < .001; torque at 30° of knee flexion: -8.8% [95% CI, -14.7 to -2.9], P = .001; time to peak torque: -17.7% [95% CI, -25.8 to -9.6], P < .001). Compared with patients with BPTB grafts, patients with QT grafts had a significantly lower LSI for all variables (mean difference: peak torque: -6.9% [95% CI, -11.2 to -2.7], P < .001; total work: -7.7% [95% CI, -12.4 to -2.9], P < .001; torque at 30° of knee flexion: -6.3% [95% CI, -12.2 to -0.5], P = .03; time to peak torque: -8.8% [95% CI, -16.9 to -0.7], P = .03). None of the graft groups reached a mean LSI of >90% for peak torque (QT: 67.5% [95% CI, 64.8-70.1]; HT: 84.9% [95% CI, 82.4-87.4]; BPTB: 74.4% [95% CI, 72.0-76.9]).

CONCLUSION

At 7 months after ACLR, patients with QT grafts had significantly worse isokinetic quadriceps strength than patients with HT and BPTB grafts. None of the 3 graft groups reached a mean LSI of >90% in quadriceps strength.

Functional leg performance 2 years after ACL surgery: a comparison between InternalBrace™-augmented repair versus reconstruction versus healthy controls

BACKGROUND

While clinical and patient-reported outcomes have been investigated in patients after InternalBrace™-augmented anterior cruciate ligament repair (ACL-IB), less is known regarding restoration of functional performance. We aimed to determine differences in functional performance within and between patients 2 years after ACL-IB, patients 2 years after ACL reconstruction (ACL-R), and healthy controls.

MATERIALS AND METHODS

A total of 29 ACL-IB, 27 ACL-R (hamstring autograft), and 29 controls performed single-leg hop (maximum forward distance hop, SLH; side hop > 40 cm in 30 s, SH), proprioception (knee joint position sense at 30° and 60° flexion), and dynamic postural balance (Y Balance) tests. Differences were calculated within groups (side-to-side difference) and between the involved leg of patients and the non-dominant leg of controls, and were evaluated to predefined statistical (P < 0.05), clinically relevant, and methodological (smallest detectable change) thresholds. The number of exceeded thresholds represented no (0), small (1), moderate (2), or strong (3) differences. In addition, the relative number of participants achieving leg symmetry (≥ 90%) and normal performance (≥ 90% of the average performance of the non-dominant leg of controls) were compared between groups (chi-squared tests, P < 0.05).

RESULTS

We observed no-to-moderate leg differences within ACL-IB (moderate difference in hops) and within ACL-R (moderate difference in knee proprioception), no leg differences between patient groups, no-to-small leg differences between ACL-IB and controls, and no leg differences between ACL-R and controls in functional performance. However, two patients in ACL-IB and ACL-R, respectively, passed the hop pretest only with their uninvolved leg, and fewer patients after ACL-IB and ACL-R than controls reached a leg symmetry and normal leg performance of controls in SLH (P < 0.001).

CONCLUSIONS

Functional performance seems to be comparable 2 years postoperatively between ACL-IB and ACL-R for a specific subgroup of patients (i.e., proximal ACL tears, moderate activity level). However, the presumed advantage of comparable functional outcome with preserved knee structures after augmented ACL repair compared with ACL-R, and the tendency of both patient groups toward leg asymmetry and compromised single-leg hop performance in the involved legs, warrants further investigation. Level of Evidence Level III, case-control study. Trial registration clinicaltrials.gov, NCT04429165 (12/09/2020). Prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04429165 .

Effects of Eccentric-Oriented Strength Training on Return to Sport Criteria in Late-Stage Anterior Cruciate Ligament (ACL)-Reconstructed Professional Team Sport Players

Background and Objectives: An effective post-injury training program is essential to regain performance and fulfill criteria for return to sport for team sport athletes following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to compare the effects of 6 weeks of eccentric-oriented strength training vs. traditional strength training during the late-stage ACL-rehab phase on leg strength and vertical and horizontal jumping performance in professional team sport athletes. Materials and Methods: Twenty-two subjects (14 males, 8 females, age 19.9 ± 4.4 years, mass 77.4 ± 15.6 kg, height 182.4 ± 11.7 cm) (mean ± SD) with a unilateral reconstructed ACL (BTB graft) were included in the study. All participants enrolled in the same rehabilitation protocol prior to the training study. Players were randomly assigned to an experimental (ECC: n = 11, age 21.8 ± 4.6 years, mass 82.7 ± 16.6 kg, height 185.4 ± 12.2 cm), and a control group (CON: n = 11, age 19.1 ± 2.1 years, mass 76.6 ± 16.5 kg, height 182.5 ± 10.2 cm). Both groups underwent an equivolumed rehabilitation program, with the only difference being in strength training, which consisted of flywheel training vs. traditional strength training for the experimental and control groups, respectively. Testing was organized before and after the 6-week training programs and included isometric semi-squat tests (ISOSI-injured and ISOSU-uninjured legs), vertical jump tests (CMJ), single-leg vertical jump tests (SLJI-injured and SLJU-uninjured legs), single-leg hop tests (SLHI-injured and SLHU-uninjured legs), and triple hop tests (TLHI-injured and TLHU-uninjured legs). In addition, limb symmetry indexes were calculated for the isometric semi-squat (ISOSLSI) test, the single-leg vertical jump (SLJLSI), and the hop (SLHLSI) tests, as well as the triple-leg hop (THLLSI) test. Results: Main effects of time across training were observed for all dependent variables (posttest > pretest, p < 0.05). Significant group-by-time interactions were found for ISOSU (p < 0.05, ES = 2.51, very large), ISOSI (p < 0.05, ES = 1.78, large), CMJ (p < 0.05, ES = 2.23, very large), SLJI (p < 0.05, ES = 1.48, large), SLHI (p < 0.05, ES = 1.83, large), and TLHI (p < 0.05, ES = 1.83, large). Conclusions: This study suggests that eccentric-oriented strength training in late-stage ACL recovery, undertaken twice or three times weekly for 6 weeks, results in better outcomes than traditional strength training in leg strength, vertical jump ability, and single and triple hop tests with injured legs in professional team sport athletes. It seems that flywheel strength training can be recommended in late-stage ACL recovery for professional team sport athletes in order to regain recommended performance outcome levels faster.

Effects of lead leg selection on bilateral landing force-time characteristics: Return to sport testing implications

We quantified the effect of lead leg selection on landing force-time characteristics during a vertical drop landing (VDL) initiated with a step-off. Plyometric-trained subjects (male: n = 8; female: n = 5; age =23 ± 3.3 years; body mass =74.4 ± 11.2 kg) performed 6 step-off-initiated VDLs from a 45-cm box (n = 3/lead leg). Pooled and lead leg stratified between-limb comparisons of limb-specific initial ground contact timing, peak vertical ground reaction force (Fz_peak ), and early landing-phase impulse (Impulse_100ms ) were assessed by a two-factor, within-subject ANOVA, and limb symmetry indexes were calculated (α = 0.05). Pooled data showed that the lead leg made contact prior to the trail leg and contributed a greater fraction to Fz_peak compared with the trail leg. Stratifying trials by lead leg selection led to significant between-limb differences in Fz_peak (p < 0.05) and Impulse_100ms (p < 0.01) with the right leg leading but not with the left leg leading. Lead leg selection in step-off-initiated VDLs influenced landing performance and limb symmetry indexes of variables associated with lower limb injury risk, suggesting the need to control for lead leg selection in these tasks. A step-off may not be a suitable technique to initiate landing tasks when assessing limb symmetry.

Can we afford to ignore the biology of joint healing and graft incorporation after ACL reconstruction?

Anterior cruciate ligament (ACL) reconstruction is successful at restoring stability to return ACL injured patients to high-demand work, sports, and recreational activities. The development of posttraumatic osteoarthritis (OA) in roughly half of patients just 10-15 years after ACLR highlight the need to improve clinical care pathways. Graft failure and reinjury rates, which further increase OA risk, also remain high for younger and more active patients. The biological components of joint recovery and graft incorporation, therefore, impact short- and long-term clinical outcomes. Biochemical and magnetic resonance imaging (MRI) data show substantial compromise of articular cartilage metabolism and matrix composition after ACL injury and reconstructive surgery suggesting a potential need for activity modulation in early recovery. Furthermore, joint recovery is variable with compositional MRI studies showing progressive cartilage degeneration 1 and 2 years after ACLR. Biopsy and MRI studies also show high variability in ACL graft characteristics within the 1st year after ACLR followed by continued graft maturation into the 2nd year and beyond. To improve the care of ACL injured patients, there is a critical need for clinical attention and scientific inquiry into timing the reintroduction of higher load activities in relationship to neuromuscular recovery, joint biology, and graft maturation. In addition to symptomatic and mechanical recovery, development and validation of biological markers for joint and cartilage homeostasis as well as ACL graft healing are needed for personalized decision making on rehabilitation needs, reduction of OA risk, and resumption of athletic, recreational, and vocational activities.

Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation

Clinical evaluation and management of anterior cruciate ligament (ACL) injury is one of the most widely researched topics in orthopedic sports medicine, giving providers ample data on which to base their practices. The ACL is also the most commonly treated knee ligament. This study reports on current topics and research in clinical management of ACL injury, starting with evaluation, operative versus nonoperative management, and considerations in unique populations. Discussion of graft selection and associated procedures follows. Areas of uncertainty, rehabilitation, and prevention are the final topics before a reflection on the current state of ACL research and clinical management of ACL injury. Level of evidence V.

Cortical Motor Planning and Biomechanical Stability During Unplanned Jump-Landings in Males With ACL-Reconstruction

CONTEXT

Athletes with anterior cruciate ligament (ACL) reconstruction exhibit increased cortical motor planning during simple sensorimotor tasks compared to healthy controls. This may interfere with proper decision-making during time-constrained movements elevating the re-injury risk.

OBJECTIVE

To compare cortical motor planning and biomechanical stability during jump-landings between participants with ACL-reconstruction and healthy individuals.

DESIGN

Cross-sectional exploratory study.

SETTING

Laboratory patients or other participants: Ten males with ACL-reconstruction (28±4 yrs., 63±35 months post-surgery) and 17 healthy males (28±4 yrs.) completed pre-planned (landing leg shown before take-off; n=43±4) and unplanned (visual cue during flight; n=51±5) countermovement-jumps with single-leg-landings.

MAIN OUTCOME MEASURES

Movement-related cortical potentials (MRCP) and frontal theta frequency power before the jump were analyzed using electroencephalography. MRCP were subdivided into three successive 0.5 sec epochs (readiness potential 1 and 2; RP and negative slope; NS) relative to movement onset (higher values indicative of more motor planning). Theta power was calculated for the last 0.5 sec prior to movement onset (higher values indicative of more focused attention). Biomechanical landing stability was measured via vertical peak ground reaction force, time to stabilization, and center of pressure.

RESULTS

Both conditions evoked MRCP at all epochs in both groups. During the unplanned condition, the ACL-reconstructed group exhibited slightly, but not significantly higher MRCP (RP-1:p=0.651, d=0.44, RP-2:p=0.451, d=0.48; NS:p=0.482, d=0.41). The ACL-reconstructed group also showed slightly higher theta power values during the pre-planned (p=0.175, d=0.5) and unplanned condition (p=0.422, d=0.3) reaching small to moderate effect sizes. In none of the biomechanical outcomes, both groups differed significantly (p>0.05). No significant condition and group interactions occurred (p>0.05).

CONCLUSIONS

Our jump-landing task evoked MRCP. Although not significant between groups, the observed effect sizes provide first indication that males with ACL-reconstruction may persistently rely on more cortical motor planning associated with unplanned jump-landings. Confirmatory studies with larger sample sizes are warranted.

TRIAL REGISTRY

clinicalTrials.gov (NCT03336060).

The Utility of Continuous Passive Motion After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Comparative Studies

Background

The application of continuous passive motion (CPM) after anterior cruciate ligament reconstruction (ACLR) was popularized in the 1990s, but advancements in the understanding of ACLR rehabilitation have made the application of CPM controversial. Many sports medicine fellowship-trained surgeons report using CPM machines postoperatively.

Purpose

To determine the efficacy of CPM use for recovery after ACLR with respect to knee range of motion (ROM), knee swelling, postoperative pain, and postoperative complications.

Study Design

Systematic review; Level of evidence, 3.

Methods

The PubMed (MEDLINE), EMBASE, Cochrane, Cumulative Index of Nursing, and Allied Health Literature databases were searched from inception to January 1, 2020, for studies with evidence levels 1 to 3 on the use of CPM for ACLR rehabilitation. Included studies were those that comparatively evaluated postoperative outcomes after ACLR between at least 2 groups of patients, with 1 having received CPM rehabilitation and the other not having received CPM.

Results

A total of 12 studies from 1989 to 2019 met the inclusion criteria. These studies included 808 patients who underwent ACLR. There was no evidence of CPM improving knee stability, final postoperative ROM, or subjective pain scores. Additionally, CPM did not lead to decreased muscle atrophy or improved International Knee Documentation Committee scores. Regarding pain medication intake during postoperative hospitalization, 2 studies found that the CPM group used less pain medication, 1 study found the CPM group used more pain medication, and 1 study found that there was no difference between the 2 groups. Complications varied widely, with 2 of 12 studies reporting complications that required a return to the operating room.

Conclusion

A clinical benefit of postoperative CPM use after ACLR was not identified in this review. While our systematic review identified a number of studies that suggest CPM use may be associated with lower usage of pain medication in hospitalized patients, this cannot be confirmed without further investigation with standardized CPM protocols and larger sample sizes. Routine CPM use after ACLR was not supported by this systematic review.

Return to Sport Composite Test After Anterior Cruciate Ligament Reconstruction (K-STARTS): Factors Affecting Return to Sport Test Score in a Retrospective Analysis of 676 Patients

BACKGROUND

Return to sport (RTS) to the preinjury level is the main purpose after anterior cruciate ligament (ACL) reconstruction but the factors affecting the RTS are not completely known. Knee Santy Athletic Return to Sport (K-STARTS) is a composite test designed to assess readiness for RTS after ACL reconstruction.

PURPOSE

To determine the key factors that influence K-STARTS scores in a large cohort of patients after ACL reconstruction.

STUDY DESIGN

Case-control study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A retrospective analysis of prospectively collected data was undertaken. All patients who underwent ACL reconstruction surgery between March 2016 and May 2017 and also had a K-STARTS assessment at 6 months postoperatively were included. To identify factors influencing the K-STARTS score, an analysis of variance was performed. Age, sex, sports level, delay between injury and surgery, concomitant lesions, graft type, additional lateral tenodesis procedure, and participation in the RTS program were analyzed to identify factors influencing the K-STARTS score.

RESULTS

A total of 676 patients were included in the study. The K-STARTS score was significantly higher in male patients than in female patients (13.9 vs 12.4; P < 0.001), in younger patients (those aged <30 years vs older patients; 14.2 vs 12; P < 0.001), ACL reconstructions performed with hamstring tendon autografts compared with bone-patellar tendon-bone (13.5 vs 13.1; P = 0.03) and in those who completed a specific RTS program in addition to standard rehabilitation, compared with those who did not participate (17.1 vs 13.1; P < 0.001). However, the only factor that significantly influenced the K-STARTS score beyond the minimal detectable change threshold was the completion of the additional RTS program. The preinjury frequency of sports participation, whether the dominant limb was injured, time from injury to surgery, the presence of associated meniscal injuries, and whether a lateral tenodesis was performed did not significantly influence the K-STARTS score.

CONCLUSION

Completion of a specific RTS program, in addition to standard rehabilitation, was the most important factor influencing the K-STARTS composite functional and psychological RTS test score at 6 months after ACL reconstruction.

CLINICAL RELEVANCE

This study shows that the completion of a specific RTS program affects positively the RTS test score at 6 months after ACL reconstruction.

Rate of Force Development Remains Reduced in the Knee Flexors 3 to 9 Months After Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Autografts: A Cross-Sectional Study

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a serious injury with a high prevalence worldwide, and subsequent ACL reconstructions (ACLR) appear to be most commonly performed using hamstring-derived (semitendinosus tendon) autografts. Recovery of maximal muscle strength to ≥90% of the healthy contralateral limb is considered an important criterion for safe return to sports. However, the speed of developing muscular force (ie, the rate of force development [RFD]) is also important for the performance of many types of activities in sports and daily living, yet RFD of the knee extensor and flexor muscles has apparently never been examined in patients who undergo ACLR with hamstring autograft (HA).

PURPOSE

To examine potential deficits in RFD, maximal muscle strength (ie, maximal voluntary isometric contraction [MVIC]), and functional capacity of ACLR-HA limbs in comparison with the healthy contralateral leg and matched healthy controls 3 to 9 months after surgery.

STUDY DESIGN

Cross-sectional study; Level of evidence: 3.

METHODS

A total of 23 young patients who had undergone ACLR-HA 3 to 9 months earlier were matched by age to 14 healthy controls; both groups underwent neuromuscular screening. Knee extensor and flexor MVIC and RFD, as well as functional capacity (single-leg hop for distance [SLHD] test, timed single-leg sit-to-stand [STS] test), were assessed on both limbs. Furthermore, patient-reported knee function (Knee injury and Osteoarthritis Outcome Score) was assessed.

RESULTS

Knee extensor and flexor MVIC and RFD were markedly compromised in ACLR-HA limbs compared with healthy contralateral limbs (MVIC for extensor and flexor, 13% and 26%, respectively; RFD, 14%-17% and 32%-39%) and controls (MVIC, 16% and 31%; RFD, 14%-19% and 30%-41%) (P < .05-.001). Further, ACLR-HA limbs showed reduced functional capacity (reduced SLHD and STS performance) compared with contralateral limbs (SLHD, 11%; STS, 14%) and controls (SLHD, 20%; STS, 31%) (P < .01-.001). Strength (MVIC) and functional (SLHD) parameters were positively related to the duration of time after surgery (P < .05), although this relationship was not observed for RFD and STS.

CONCLUSION

Knee extensor and flexor RFD and maximal strength, as well as functional single-leg performance, remained substantially reduced in ACLR-HA limbs compared with noninjured contralateral limbs and healthy controls 3 to 9 months after reconstructive surgery.

Compliance in post-operative rehabilitation is a key factor for return to sport after revision anterior cruciate ligament reconstruction

PURPOSE

To assess the rate of return to sport (RTS) following revision Anterior Cruciate Ligament Reconstruction (ACLR) in a rehabilitation-based cohort of patients. A secondary goal of the study was to evaluate the association between compliance in post-operative rehabilitation and RTS rate.

METHODS

The study cohort included 79 sport-active patients (62 males, 17 females, 30.0 ± 10.2 years old) who underwent revision ACLR surgery and followed the same functional-oriented rehabilitation protocol. Patients were evaluated using a RTS survey: return to any kind of sport participation, return to the same pre-injury sport, return to the same sport at the same pre-injury level. With regards to compliance in post-operative rehabilitation, patients were then grouped in (1) Fully Compliant (FC), (2) Moderately Compliant (MC), (3) Scarcely Compliant (SC), and (4) Non-Compliant (NC).

RESULTS

At an average follow-up of 29 ± 12 months, 86% of the patients returned to some kind of sport activity, 62% returned to the same pre-injury sport activity and 59% returned to the same pre-injury level of sport activity. While no surgical aspects were correlated with RTS, higher BMI was found to have a negative influence (p = 0.033). Regardless of the type of sport, compliance significantly affected RTS at the same pre-injury level (p = 0.006): 86% in FC, 67% in MC, 50% in SC, and 45% in NC. For each compliance goal achieved, the probability of RTS increased by 68% (OR = 1.68; p = 0.027).

CONCLUSION

RTS at the same pre-injury level after revision ACLR is challenging. A higher compliance in rehabilitation significantly increases the chances of RTS.

LEVEL OF EVIDENCE

IV.

THE EFFECT OF TRAINING ON A COMPLIANT SURFACE ON MUSCLE ACTIVATION AND CO-CONTRACTION AFTER ANTERIOR CRUCIATE LIGAMENT INJURY

BACKGROUND

Performing physical activities on compliant surfaces alters joints kinematics by decreasing joint motions. However, the effect of administering a training program on a compliant surface on muscle activities after anterior cruciate ligament (ACL) injury is unknown.

HYPOTHESIS/PURPOSE

To compare the effects of training on a compliant surface and manual perturbation training on individual muscle activation and muscle co-contraction indexes after an ACL injury. It was hypothesized that patients who received training on the compliant surface would demonstrate higher individual and combined muscle activities compared to the manual group.

METHOD

Sixteen patients (participated in level I/II sports) who sustained an ACL injury and had not undergone reconstructive surgery participated in this preliminary study. Eight patients received training on a compliant surface (Compliant group) and data of eight patients matched by age and sex from a previous study who received manual perturbation training were used as a control group (Manual group). Patients in both groups completed standard three-dimensional gait motion analysis with surface electromyography (EMG) of several lower extremity muscles during gait. Muscle co-contraction index and individual muscle activations were computed during weight acceptance (WA) and mid-stance (MS) intervals. A 2x2 analysis of variance (ANOVA) was used with an alpha level of p<0.10 to account for the high EMG variability.

RESULTS

The compliant group significantly increased muscle co-contraction of vastus lateralis-lateral hamstring (VL-LH), vastus medialis-gastrocnemius medialis (VM-MG), and vastus lateralis (VL) muscle activity during WA (p ≤ 0.035) and manual group significantly decreased VM-MG muscle co-contraction during WA (p=0.099) after training.

CONCLUSION

Administering training on a compliant surface provides different effects on muscle activation compared to manual perturbation training after an ACL injury. Training on a compliant surface caused increased muscle co-contraction indexes and individual muscle activation, while manual perturbation training decreased the VM-MG muscle co-contraction index.

LEVEL OF EVIDENCE

2b.

Massage therapy protocol for post-anterior cruciate ligament reconstruction patellofemoral pain syndrome: a case report

Background:

The intent of the present study was to determine the effectiveness of massage therapy in the rehabilitation of post–anterior cruciate ligament reconstruction patellofemoral pain syndrome. The primary complications following surgical repair of the anterior cruciate ligament—classified as patellofemoral pain syndrome—are hamstring flexion contracture and quadriceps weakness, leading to patellofemoral dysfunction and retropatellar pain.

Methods:

Treatment included lymphatic drainage, myofascial release, neuromuscular techniques including trigger point release, muscle energy techniques and cross-fiber friction. Orthopedic physical assessment tests were used to chart changes in patellofemoral function and changes in range of motion in the knee during the course of the massage interventions. Subjective reporting on pain level and function were also documented.

Results:

A decrease in pain level, hamstring flexion contracture and lateral tracking of the patella were documented.

Conclusion:

Massage therapy was determined to be an effective complementary therapy in the treatment of patellofemoral pain syndrome.