Knee Proprioception Research Articles

Comparison of unilateral and bilateral strength ratio, strength, and knee proprioception in older male fallers and non-fallers

BackgroundAsymmetry of lower limb muscle strength and knee proprioception have been linked with risk of falling among elderly with and without history of falling. ObjectiveThis study aimed to determine the comparison of hamstrings to quadriceps strength ratio (CSR) and bilateral knee strength ratio, hamstrings and quadriceps muscles' strength and knee proprioception in elderly male fallers and non-fallers. MethodsSixty older adults, 65 years and older were recruited into faller (fell twice in the last six months) and non-faller groups. Then, the knee extension and flexion strength and proprioception at 45° knee flexion for the dominant leg (DL) and non-dominant legs (NDL) were measured with a Biodex Isokinetic Dynamometer. ResultsThe strength of quadriceps and hamstring muscles showed significantly higher values in DL by 5.4 %, 9.2 % and NDL by 11.7 %, 15.5 % in the non-faller compared to the faller (p < 0.05). Significantly greater bilateral asymmetry (>10 % difference) was observed with the quadriceps (p = 0.014, −7.9 %, ES = 0.76) and hamstrings (p < 0.001, −18.4 %, ES = 1.5) as well as reduced CSR (<72 %) by 7.6 % in DL (ES = 0.64) and 11.3 % in NDL (ES = 0.81) with fallers versus non-fallers. Significantly less knee proprioception was found with the DL by −1.5 % (ES = 1.15) and NDL (ES = 1.50) by −2.1 % (p < 0.001) in non-faller compared to faller. ConclusionIt concluded that non-fallers have better strength symmetry, bilateral and unilateral knee strength ratios as well as more sensitive knee proprioception than fallers. It is suggestive that older adult fallers may need to improve bilateral knee strength symmetry and proprioception to prevent the risk of falling.

A prospective study of joint position sense after anterior cruciate ligament injury, reconstruction with a bone-patella tendon-bone graft, and rehabilitation

BackgroundDisruption of the anterior cruciate ligament (ACL) is associated with significant biomechanical and neuromuscular changes including deficits in joint proprioception. While previous studies have assessed joint position sense (JPS) in ACL deficient knees, methods have varied and few have done so with prospective study designs. The specific aim of this investigation was to determine the effect(s) of ACL reconstruction and recovery time may have on JPS. MethodsIn this prospective study, we assess the effects of ACL reconstruction and rehabilitation on joint position sense in a temporal study. Twelve patients with unilateral ACL injuries were assessed pre-operatively and at 2, 4, 8 months post-op. JPS measurements were performed, while the subject was standing, with passive-active (P-A) and active-active (A-A) tests. Comparisons between the injured/reconstructed and contralateral, uninjured knee were evaluated in terms of real and absolute mean errors. ResultsThere were no statistically significant differences between the injured/reconstructed and contralateral/normal side with P-A or A-A testing at 2, 4, or 8 months. ConclusionWe conclude that there is no difference in joint position sense between the injured and contralateral leg after ACL disruption and reconstruction beginning as early as 2 months post-op. This study provides further evidence that knee proprioception is not altered by ACL injury and reconstruction. Level of evidence: II.

Right hemisphere brain lateralization for knee proprioception among right-limb dominant individuals.

Studies indicate that brain response during proprioceptive tasks predominates in the right hemisphere. A right hemisphere lateralization for proprioception may help to explain findings that right-limb dominant individuals perform position matching tasks better with the non-dominant left side. Evidence for proprioception-related brain response and side preference is, however, limited and based mainly on studies of the upper limbs. Establishing brain response associated with proprioceptive acuity for the lower limbs in asymptomatic individuals could be useful for understanding the influence of neurological pathologies on proprioception and locomotion. We assessed brain response during an active unilateral knee joint position sense (JPS) test for both legs of 19 right-limb dominant asymptomatic individuals (females/males = 12/7; mean ± SD age = 27.1 ± 4.6 years). Functional magnetic resonance imaging (fMRI) mapped brain response and simultaneous motion capture provided real-time instructions based on kinematics, accurate JPS errors and facilitated extraction of only relevant brain images. Significantly greater absolute (but not constant nor variable) errors were seen for the dominant right knee (5.22° ± 2.02°) compared with the non-dominant left knee (4.39° ± 1.79°) (P = 0.02). When limbs were pooled for analysis, significantly greater responses were observed mainly in the right hemisphere for, e.g., the precentral gyrus and insula compared with a similar movement without position matching. Significant response was also observed in the left hemisphere for the inferior frontal gyrus pars triangularis. When limbs were assessed independently, common response was observed in the right precentral gyrus and superior frontal gyrus. For the right leg, additional response was found in the right middle frontal gyrus. For the left leg, additional response was observed in the right rolandic operculum. Significant positive correlations were found between mean JPS absolute errors for the right knee and simultaneous brain response in the right supramarginal gyrus (r = 0.464, P = 0.040). Our findings support a general right brain hemisphere lateralization for proprioception (knee JPS) of the lower limbs regardless of which limb is active. Better proprioceptive acuity for the non-dominant left compared with the dominant right knee indicates that right hemisphere lateralization may have meaningful implications for motor control.

Effectiveness of retro walking on knee proprioception after knee injury

Background: Knee injuries are frequent and can significantly affect a person’s functionality and capacity to carry out regular tasks. Only two of the many components that support the equilibrium of the knee joint are ligaments and supporting structures. Direct or indirect trauma can cause ligament injuries that result in instability, and sports and physical activity put the knee joint at a higher risk for injury. Proprioception, the body’s ability to recognize its location in space, is crucial for preserving balance and coordinating motions. Walking is a fundamental action that may be employed for rehabilitation, both forward and backward. The aim of the study is to investigate how retro walking after a knee injury affects knee proprioception. Finding out how retro walking impacts knee health is one of the objectives. The objectives include comparing the experimental group’s findings to those of a control group and determining how retro walking affects knee proprioception. Retro walking increases knee proprioception as well as the neuromuscular and muscular systems, which may make rehabilitation programs for those with knee injuries more effective. Objective: The study’s objective is to evaluate how retro walking after a knee injury affects knee proprioception. The objectives include comparing the experimental group’s findings to those of a control group and determining how retro walking affects knee proprioception. Retro walking increases knee proprioception as well as the neuromuscular and muscular systems, which may make rehabilitation programs for those with knee injuries more effective. Method: 24 injured individuals (men and women) participated in this experimental investigation. They were split into two groups of 14, the control group, and the experimental group, obtaining everyone’s approval after having informed them. The knee injury and osteoarthritis scale (KOOS), star excursion balancing test, and joint position sense are employed as outcome measures. Prior to the intervention, baseline measurements were collected. After 6 weeks of interventions, the final grade was determined. While stationary cycling and strengthening exercises for the quadriceps, calf muscles, and hamstrings are part of traditional therapy among the control group, retro walking was also offered to the experimental group. Results were collected, and the data were examined after 6 weeks. Result: The experiment group of knee injury patients who performed retro walking demonstrated a substantial increase in knee function and proprioception ratings, according to the study’s findings. According to the analysis of the KOOS scale, scores for proprioception and knee function after retro walking were significantly different, with a mean change of −19.833 units. Retro walking’s ability to enhance knee proprioception was further supported by the SEBT score, which showed a mean change of −37.167 units. A substantial mean change of −4.583 units was also seen when the JPS score was evaluated, showing the beneficial effects of retro walking on knee proprioception in knee injury patients. These results imply that retro walking is a viable option for enhancing proprioception and knee functionality in knee injury patients. 34 Conclusion: It has been found that retro walking on a treadmill for 15 min, up to 6 weeks at 3 times each week, with a 10◦ inclination and a speed of 1–2 m/s, significantly improves knee proprioception following injury. The statistical study supports this observation. Considering the study’s results, one may assert that retro walking helps knee injury patients raise their total level of physical activity. It has been demonstrated that retro walking enhances knee function and proprioception. Analysis of differences between both the test and control groups, the joint position awareness, star excursion balance test, and KOOS score all show greater progress. Retro walking is therefore more successful in the rehabilitation of post-knee injury in the current investigation.

Comparison of proprioception, strength, and dynamic balance between aquatic and cycling trainings after arthroscopic partial meniscectomy during early rehabilitation in young male athletes

Arthroscopic partial meniscectomy (APM) strives to preserve knee biomechanics and function after the meniscal rupture. However, patients undergoing APM experience long-term impacts like proprioceptive deficit and functional decline. This study aimed to examine and compare the effects of aquatic and leg cycling trainings on young athletes undergone APM. Ninety-seven male athletes with APM were assigned to aquatic training group (ATG, n = 49) and cycling training group (CTG, n = 48). Both intervention trainings were conducted three times a week for 6 weeks after 2 weeks of APM. The rehabilitation training was the same in each session. The International Knee Documentation Committee (IKDC) questionnaire scores, knee joint position sense, Y-balance test, and isokinetic knee strength were measured before and after the interventions. Significant improvements were observed after the trainings regarding measured variables for both ATG and CTG groups. Comparison of the two groups found that ATG group had higher scores in IKDC and Y-balance test, greater muscle power, and lower absolute error in the joint position sense test compared to the CTG group. ATG and CTG are thus considered effective training interventions in early rehabilitation phase following the APM. Moreover, ATG may be more conducive than CTG in improving subjective knee symptoms, proprioception, and muscle power.

Supervised, Heavy Resistance Training Is Tolerated and Potentially Beneficial in Women with Knee Pain and Knee Joint Hypermobility: A Case Series.

Adults with generalised joint hypermobility including knee joint hypermobility (GJHk) report more knee joint symptoms when compared to adults without GJHk. There is no consensus on best practice for symptom management. For instance, controversy exists regarding the appropriateness and safety of heavy resistance training as an intervention for this specific group. This case series aims to describe a supervised, progressive heavy resistance training program in adults with GJHk and knee pain, the tolerability of the intervention, and the outcomes of knee pain, knee-related quality of life, muscle strength, proprioception, and patellar tendon stiffness through a 12-week period. Adults with GJHk and knee pain were recruited to perform supervised, progressive heavy resistance training twice a week for 12 weeks. The main outcome was the tolerability of the intervention. Secondary outcomes were knee pain during a self-nominated activity (VASNA); Knee injury and Osteoarthritis Outcome Score (KOOS); Tampa Scale of Kinesiophobia (TSK); maximal quadriceps voluntary isometric contraction and rate of torque development; 5 repetition maximum strength in five different leg exercises; single leg hop for distance; knee proprioception and patellar tendon stiffness. In total, 16 women (24.2 years, SD 2.5) completed at least 21/24 training sessions. No major adverse events were observed. On average, VASNA decreased by 32.5 mm (95% CI 21.4-43.6), in addition to improvements in KOOS and TSK scores. These improvements were supported by an increase in all measures of lower extremity muscle strength, knee proprioception, and patellar tendon stiffness. Supervised heavy resistance training seems to be well tolerated and potentially beneficial in young women with GJHk and knee pain.

Effects of compression running pants and treadmill running stages on knee proprioception and fatigue-related physiological responses in half-marathon runners.

Background: Knee injury is common in half-marathon runners, however, the effect of compression running pants on fatigue and knee proprioception remains unclear. Objectives: The study aims to investigate whether wearing compression running pants (CRP) and treadmill running stages affect knee proprioception and fatigue-related physiological responses during half-marathon running. Methods: Eighteen half-marathon runners completed two self-paced 21km treadmill running trials, once wearing CRP and once wearing loose running shorts (LRS). For each 21km run, RPE, heart rate, blood lactic acid, and knee flexion proprioception were assessed before starting, and after each 7km stage. Results: Data analysis revealed no difference between CRP and LRS conditions in heart rate, RPE, or blood lactic acid. Repeated measures ANOVA showed a significant garment condition main effect whereby wearing CRP was associated with higher knee proprioceptive acuity (p = 0.006). Polynomial trend analysis showed a significant linear downwards trend in proprioceptive acuity across the four measurement occasions (p = 0.048). Stage analysis showed that wearing CRP was associated with better knee proprioception at running distances of 14km (p = 0.007, 95%CI = -0.054, -0.010) and 21km (p = 0.016, 95%CI = -0.051, -0.006). Conclusion: Compression running pants provide an overall positive effect on knee proprioception, particularly after 14km and 21km, which may reduce the probability of knee injury. CRP had no significant effect on physiological measures in half-marathon running.

Comparison of proprioception recovery following anterior cruciate ligament reconstruction using an artificial graft versus an autograft

BackgroundTo compare proprioception recovery after anterior cruciate ligament reconstruction (ACLR) with a hamstring tendon autograft versus the artificial Ligament Advanced Reinforcement System (LARS).Material and methodsForty patients (9 females, 31 males) with anterior cruciate ligament (ACL) rupture were enrolled in this prospective study. Patients were randomized to two groups, 1) ACLR using a hamstring tendon autograft (n = 20) or 2) ACLR using artificial LARS (n = 20). Proprioception was assessed with knee joint position sense (JPS) passive-passive test at 45° and 75° flexions, with the contralateral healthy knee as a control baseline to calculate the JPS error. Knee JPS absolute error was used as the main outcome variable and defined as the absolute difference between the reproduction and target angles.ResultsJPS error in both groups at 3 months after ACLR was significantly higher than that at 12 months. However, no significant difference in JPS error was detected between the LARS and autograft groups at either 3 or 12 months after ACLR. Analyzing JPS data by grouping patients according to whether ACLR was performed more or less than 1 year following injury regardless of graft type showed a statistically significant difference between the groups at 3 months, but not at 12 months, after ACLR. Patients receiving the graft within 1 year of injury had a lower JPS error than those receiving the graft more than 1 year after injury at 3 months. No complications were associated with either ACLR method.ConclusionACLR with a hamstring tendon autograft or LARS artificial graft is similarly safe and effective for recovering knee proprioception.

Factors associated with falls in patients with knee osteoarthritis: A cross-sectional study.

Falls represent an important adverse effect associated with knee osteoarthritis and result in a significant financial burden on the healthcare system. Therefore, identification of fall predictors is essential to minimize fall incidence. However, few studies have investigated falls and fall predictors, particularly focused on the fear of falls and proprioception. In this study, we investigated significant fall predictors in patients with knee osteoarthritis in Malang, Indonesia. Our findings may serve as useful guidelines to develop geriatric fall prevention programs. This cross-sectional survey using purposive sampling was performed between April and July 2021 and included 372 participants. We recorded the following data: sociodemographic and medical history questionnaire responses, visual analog scale scores, Hopkins falls grading scale scores, Fall Efficacy Scale-International scores, proprioception test findings, knee injury and osteoarthritis outcome score (KOOS), range of motion (ROM), chair stand test and the timed up and go test performance. Data were analyzed using the chi-square and t tests, and multivariate logistic regression to determine significant fall predictors. Multivariate logistic regression analysis showed a lower risk of falls in patients with better proprioception and ROM than in the other groups (odds ratio 0.55 vs 0.96). The risk of falls was higher in patients with higher KOOS symptoms, fear of falls, diagnosis of low back pain and diabetes mellitus, and increased body mass index than in the other groups (odds ratio 1.41, 2.65, 1.27, 3.45, and 1.10, respectively. Our study shows that knee proprioception and ROM serve as protective factors against falls, whereas KOOS symptoms, fear of falls, low back pain, diabetes mellitus, and body mass index were associated with a high risk of falls, with diabetes mellitus and fear of falls being the most significant risk factors. These findings may be useful to policy makers to develop a fall prevention program that can be implemented in community health care centers across Indonesia to deliver individualized, person-centered care and improve fall prevention strategies through a systematic process comprising evaluation, intervention, and monitoring to minimize fall risk.

Screening Clinical Changes for the Diagnosis of Early Knee Osteoarthritis: A Cross-Sectional Observational Study.

Background: The main objective was to evaluate differences in the clinical, motor, or functional variables in patients with Early Osteoarthritis (EOA) and individuals at risk of developing osteoarthritis (OA). Methods: A cross-sectional study was performed. All the participants were divided into two groups: EOA patients and healthy subjects (HS) at risk of developing OA. The main outcomes were clinical tests, such as those of knee morphology, instability, or proprioception; motor and functional variables, such as knee strength, range of motion, walking speed, and the sit-to-stand test; pain and disability, assessed through the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and Knee injury and Osteoarthritis Outcome Score (KOOS) scales; and knee alignment and leg length inequality, assessed via X-ray images. Results: A total of 97 participants were included (54 EOA and 43 HS). Patients with EOA showed a greater presence of knee pain (p &lt; 0.01). In addition, more EOA patients showed instability both in the left (p &lt; 0.01) and right legs (p &lt; 0.05). Regarding the knee alignment variable, significant differences were found (p &lt; 0.04), with more patients with EOA diagnosed as possessing a varus alignment. In addition, EOA patients showed lower knee strength, since statistically significant differences were found regarding flexion and extension strength in the left leg (Mean Difference (MD): 12.92; p = 0.03; d = -0.46 and MD:7.81; p = 0.04; d = -0.39). Differences were found for the sit-to-stand test scores, showing lower results for the EOA group (MD: -1.91; p &lt; 0.01; d = 0.54). Conclusions: The results of this research show statistically significant differences between patients with EOA and HS at risk of developing OA with respect to pain, disability, instability, knee strength, and the sit-to-stand test. Our results suggest that the evaluation of clinical, motor, and functional features could contribute to an early management of knee OA.

Importance of Lower Extremity Muscle Performance and Knee Proprioception During First 60 Degrees of Knee Flexion at Three Months After Anterior Cruciate Ligament Reconstruction

Background: Knee proprioception and neuromuscular control may be important factors contributing to re-injury occurrences. Objectives: To examine lower extremity muscular performance and knee proprioception preoperatively and 3 months after anterior cruciate ligament (ACL) reconstruction. Methods: Twelve participants underwent ACL reconstruction using the hamstring tendon. All participants were assessed for knee proprioceptive sense using an isokinetic dynamometer at 15° and 60° of knee flexion. Lower extremity muscular performance was examined using the single-leg squat test (SLS) with two-dimensional motion analysis in frontal and sagittal planes. Results: Mean absolute error angle at a 15-degree-target angle was significantly lower at three months after ACL reconstruction compared with the preoperative state (P = 0.04). Maximal knee flexion angle of the injured The SLS test showed a lesser knee flexion angle of the injured knee at three months after ACL reconstruction (P = 0.01), and injured knee proprioception at 60 degree-flexion did not significantly improve at the three month-postoperative stage. Conclusions: At three months after ACL reconstruction by hamstring graft tendon, knee proprioceptive sense at an inner range of knee extension improved. However, proprioception at the middle range did not significantly develop. The range of hip and knee motions using SLS related to strength changes that the knee extensor needs to improve, especially in the middle range.

The Effects of Self-Myofascial Release on Hamstring and Gastrocnemius Muscles Using Foam Roll on Postural Sway, Knee Proprioception, and Dynamic Balance in Recreationally Active Females

Poor joint proprioception and balance maintenance may lead to sports injuries. Numerous studies have indicated that self-myofascial release (SMR) can improve the function of the proprioception and balance systems. Thus, this study aimed to investigate the effects of acute bouts of SMR on the center of pressure displacements during four stance positions, knee joint position sense at 45° and 90° in open kinetic chain tasks, and dynamic balance during the Y-balance test. Forty-two recreationally active females aged 20–25 years were assigned to either the foam roll group performing 1 min × 3 sets of SMR in the posttest session (N = 22) or the control group (N = 20). Joint position sense at 90° (p = .021), dynamic balance in the anterior (p = .007) and posterolateral (p &lt; .001) directions, as well as the composite score (p = .001), improved significantly in the foam roll group. According to the findings, SMR may improve knee joint position sense at 90° and dynamic balance without any significant impacts on postural sway.

Combined balance and plyometric training enhances knee function, but not proprioception of elite male badminton players: A pilot randomized controlled study.

ObjectivesTo investigate the effect of combined balance and plyometric training on knee function and proprioception of elite badminton athletes.MethodsSixteen elite male badminton players (age: 20.5 ± 1.1 years, height: 177.8 ± 5.1 cm, weight: 68.1 ± 7.2 kg, and training experience: 11.4 ± 1.4 years) volunteered to participate and were randomly assigned to a combined balance and plyometric training (CT) (n = 8) and plyometric (PT) group (n = 8). The CT group performed balance combined with plyometric training three times a week over 6 weeks (40 min of plyometrics and 20 min of balance training); while the PT group undertook only plyometric training for the same period (3–4 sets × 8–12 reps for each exercise). Both groups had the same technical training of badminton.ResultsThe knee function and proprioception were assessed at baseline and after the intervention by measuring the performance of single-legged hop tests (LSIO, LSIT, LSIC, LSIS), standing postural sway (COPAP, COPML), and LSI of dominant leg and non-dominant leg. The results showed that as compared to PT, CT induced significantly greater improvements in LSIT and LSIS (p < 0.001) and significant greater percent increase in NAP (p = 0.011). The changes in LSIO, LSIC, DAP, NAP, LSIAP, DML, NML, and LSIML induced by CT did not differ from that induced by PT (p > 0.213).ConclusionIn elite badminton players, intervention using CT holds great promise to augment the benefits for knee function compared to the intervention using PT only, and at the same time, with at least comparable benefits for proprioception. Future studies are needed to examine and confirm the results of this study.

Various methods to assess knee proprioception

Introduction: Proprioception is a vital aspect of motor control and when degraded or lost can have a profound impact on function in diverse clinical populations. This systematic review aimed to identify clinically related tools to measure proprioceptive acuity. The major purpose of this systematic review was to identify and categorise the methods that have been developed and utilised to test proprioceptive accuracy in a comprehensive manner. Methods: The pub med, Scopus, Web of Science and the other search engine/databases used: Cochrane database / SCIRE / PEDro / CINAHL/ EMBASE, ERIC were systematically searched. Conclusions: The TTDPM method has less relative ecological validity, but has high conceptual purity, Although JPR tests may have less relative test validity, but more clinically feasible, The AMEDA method appears to have better ecological validity and relatively better test validity and data validity.

Paper 84: Differences in Metrics of Knee Joint Loading Between Individuals Following a Primary Anterior Cruciate Ligament Repair (ACL-R) Surgery Versus Those Who Underwent a Standard ACL Reconstruction with a Patella Bone-Tendon-Bone Autograft (ACLR)

Objectives:Recent research suggests that the short- and long-term outcomes following Anterior Cruciate Ligament Reconstructions (ACLR) on knee joint health are worse than originally thought. The ACLR procedure may result in or expediate the arthritic process through a variety of factors including prolonged underloading of the knee joint following surgery. These recent findings have resulted in a renewed interest in the ACL repair (ACL-r) procedure as a potentially more joint “friendly” secondary to less surgical trauma with the preservation of the native ACL ligament. In several animal models and in human clinical data, ACL remnant preservation and ACL entire ligament repair/preservation has been shown to benefit lower extremity and knee biomechanics, proprioception, and short term clinical outcomes. However, there is limited data on the newer ACL-r techniques and their subsequent outcomes on knee joint loading. Therefore, the purpose of this study was to assess for differences in metrics of knee joint loading between individuals following a primary anterior cruciate ligament repair (ACL-r) surgery versus those who underwent a standard ACL reconstruction with a patella bone-tendon-bone autograft (ACLR).Methods:A total of 30 participants were enrolled into this study [ACL-r n: 15, age(yrs): 38.8±13.9, Ht(cm): 173.4±10.0, Wt(kg): 77.9±17.5; ACLR: n: 15, age(yrs): 25.60±1.7, Ht(cm): 173.5±10.3, Wt(kg): 75.4±15.6]. Participants in ACL-r group all sustained a proximal ACL disruption (Sherman Classification Type 1 or 2) that was amenable to repair and underwent primary ACL repair with suture fixation. ACL-r was performed under arthroscopic visualization with 2 or 3 standard portals in a technique similar to that described by van der list, MD (2017), but modified by the senior author to include only one 4.75mm swivelock (Arthrex) secured in the anterior aspect of the native footprint on the medial wall of the lateral femoral condyle. Participants in the ACLR group all underwent a primary ACLR with patella bone-tendon-bone autograft. The autograft bone blocks were crimped to 9mm and then two 10mm femoral and tibial tunnels created for the graft. An independent tunnel technique, utilizing the medial portal for creation of the femoral socket within the native ACL femoral attachment site, was performed in all ACLR patients. At 12 weeks following surgery participants in both groups completed the IKDC questionnaire and biomechanical testing with two AMTI force plates and a 10 camera Qualisys motion capture system. Peak knee extension moment (Nm/Ht*Wt) and total knee joint power (Watt/Ht*Wt) as a measure of eccentric loading (contraction) during the descent phase of a single-leg squat were calculated on the surgical limb and averaged across the middle three trials. Participants also completed quadriceps strength testing on both limbs (surgical and non-surgical) on an isokinetic dynamometer at 60 °/sec. The average peak torque of five repetitions were used to calculate a limb symmetry index (LSI) [Surgical/NonSurgical X100]. Independent t-tests were used to assess for differences between groups in three metrics. For descriptive purposes a separate independent t-test was used to assess for differences in age, height, mass, and IKDC scores. Statistical significance was set at P< 0.05 for all analyses.Results:There were no differences in height (p=0.996), mass(p=.678), or IKDC ( p=0.886) scores between the groups; however, there was a significant difference in age (p=0.009). The ACL-r had a significantly greater peak knee extension moment (ACL-r: -0.078±0.02; ACLR: -0.059±.02; p=0.014) and total knee joint power (ACL-r-0.03±0.01; ACLR: -0.02±0.01, p=0.016) than the ACLR group. The ACL-r also had a significantly great quadriceps LSI than the ACLR group (ACL-r: 65.09±20.4, ACLR: 49.2±11.4, p=0.014).Conclusions:The results of this study indicate that those individuals following ACL-r demonstrate increased knee joint loading during a single leg squat task compared to those who underwent ACLR. Decreases in knee extension moment have been reported across a variety of tasks and across a variety of time points following ACLR. Furthermore, decreased knee extension moments have been associated with movement profiles that have been linked to cartilage degeneration following ACLR. The improved knee extension moment in the ACL-r group at this early time may indicate a positive change in joint loading and potentially a decreased rate of cartilage degeneration. Knee joint total power accounts for both knee moment and angular velocity, indicating improved knee loading throughout the entire eccentric movement in the ACL-r group and further supports the notion of improved knee joint loading following ACL-r compared to ACLR. Decreased quadriceps muscle strength has been associated with changes in cartilage structure and it has been suggested that maximizing muscle strength in the first 6 months following surgery may promote improved cartilage healing, thus the increased quadriceps LSI in the ACL-r may be protective early in the recovery process.

Changes in Dynamic Postural Stability After ACL Reconstruction: Results Over 2 Years of Follow-up.

Background:The anterior cruciate ligament (ACL) is crucial for knee proprioception and postural stability. While ACL reconstruction (ACLR) and rehabilitation improve postural stability, the timing in improvement of dynamic postural stability after ACLR remains relatively unknown.Purpose:To evaluate changes in dynamic postural stability after ACLR out to 24 months postoperatively.Study Design:Case series; Level of evidence, 4.Methods:Patients undergoing ACLR were prospectively enrolled, and dynamic postural stability was assessed within 2 days before surgery, at 3-month intervals postoperatively to 18 months, then at 24 months. Measurements were made on a multidirectional platform tracking the patient’s center of mass based on pelvic motion. The amount of time the patient was able to stay on the platform was recorded, and a dynamic motion analysis score, reflecting the patient’s ability to maintain one’s center of mass, was generated overall and in 6 independent planes of motion.Results:A total of 44 patients with a mean age of 19.7 ± 6.2 years completed the study protocol. Overall mean dynamic postural stability improved significantly at 3, 6, 9, and 12 months after surgery, with continued improvement out to 24 months. Notable improvements occurred in medial/lateral and anterior/posterior stability from baseline to 6 months postoperatively, while internal/external rotation and flexion/extension stability declined initially after surgery from baseline to 3 months postoperatively before stabilizing to the end of the study period.Conclusion:Overall dynamic postural stability significantly improved up to 12 months after ACLR. Improvement in postural stability occurred primarily in the medial/lateral and anterior/posterior planes of motion, with initial decreases in the flexion/extension and internal/external rotational planes of motion.

Primary Repair for Treating Acute Proximal Anterior Cruciate Ligament Tears: A Histological Analysis and Prospective Clinical Trial.

Reconstruction surgery for acute proximal anterior cruciate ligament (ACL) tears remains controversial. Recently, ACL primary repair has received increasing attention in ACL treatment. This study aimed to explore the histological characteristics of ACL healing in primary repair and compare its therapeutic and prognostic results with the reconstruction of acute proximal ACL tears. Histological experiments using rabbits and a prospective clinical trial were conducted. We established a rabbit model of ACL primary repair, and histological changes were observed using haematoxylin and eosin (HE) and toluidine blue staining. We performed immunohistochemical analysis of CD34 and S-100 and measured the expression of collagen I and II using qRT-PCR, Western blotting, and immunohistochemistry. The prospective clinical trial involved performing ACL primary repair and reconstruction in patients with acute proximal ACL tears to detect proprioception and evaluate the function of joints. We discovered that primary repair promoted cell proliferation in the tendon-bone transition and ligament portions, reduced osteoarthritis-like pathological changes, and maintained blood vessels and proprioceptors within the ACL. In the clinical trial, primary repair achieved similar therapeutic outcomes, including recovery of knee function and proprioception, in the follow-up period as ACL reconstruction. However, the primary repair had a significantly shorter operative time and lower cost than reconstruction. Therefore, doctors should consider the benefit of primary repair in treating acute proximal ACL tears.

Neuromuscular Training, Exercise Physiology Clinic, Real-time Exercise, and Cardiac Rehabilitation

Neuromuscular Training, Exercise Physiology Clinic, Real-time Exercise, and Cardiac Rehabilitation

Brain Response to a Knee Proprioception Task Among Persons With Anterior Cruciate Ligament Reconstruction and Controls.

Knee proprioception deficits and neuroplasticity have been indicated following injury to the anterior cruciate ligament (ACL). Evidence is, however, scarce regarding brain response to knee proprioception tasks and the impact of ACL injury. This study aimed to identify brain regions associated with the proprioceptive sense of joint position at the knee and whether the related brain response of individuals with ACL reconstruction differed from that of asymptomatic controls. Twenty-one persons with unilateral ACL reconstruction (mean 23 months post-surgery) of either the right (n = 10) or left (n = 11) knee, as well as 19 controls (CTRL) matched for sex, age, height, weight and current activity level, performed a knee joint position sense (JPS) test during simultaneous functional magnetic resonance imaging (fMRI). Integrated motion capture provided real-time knee kinematics to activate test instructions, as well as accurate knee angles for JPS outcomes. Recruited brain regions during knee angle reproduction included somatosensory cortices, prefrontal cortex and insula. Neither brain response nor JPS errors differed between groups, but across groups significant correlations revealed that greater errors were associated with greater ipsilateral response in the anterior cingulate (r = 0.476, P = 0.009), supramarginal gyrus (r = 0.395, P = 0.034) and insula (r = 0.474, P = 0.008). This is the first study to capture brain response using fMRI in relation to quantifiable knee JPS. Activated brain regions have previously been associated with sensorimotor processes, body schema and interoception. Our innovative paradigm can help to guide future research investigating brain response to lower limb proprioception.

Correlation of eccentric strength of the knee extensors and knee proprioception with dynamic postural control.

It is important for clinicians and researchers to perform dynamic postural control evaluation for predicting musculoskeletal conditions, injury prevention, and rehabilitation. The purpose of this study was to investigate the relationship (1) between the eccentric strength of the knee extensors and star excursion balance test (SEBT), and (2) between the knee proprioception and SEBT. Forty healthy young adults participated in this study. The eccentric peak torque (EPT) of the knee extensors, joint position sense, and force sense were measured. The participants also performed SEBT. Pearson's product-moment correlation and multiple linear regression analysis were used to determine the relationship between the variables and SEBT. The posteromedial direction of the SEBT was positively and strongly correlated with EPT (r= 0.74, P< 0.01). The anterior and posterolateral directions were positively and moderately correlated with EPT (r= 0.46, P< 0.01, and r= 0.69, P< 0.01, respectively.). However, knee proprioception was not correlated with all the directions of SEBT (P> 0.05). According to the results of multiple linear regression analysis, EPT of the knee extensors significantly predicted SEBT reach distances. The eccentric strength of the knee extensors seems to be an essential factor in dynamic postural control. However, the knee proprioception did not show a significant correlation with SEBT.