Effects of an Exercise Therapy Targeting Knee Kinetics on Pain, Function, and Gait Kinetics in Patients With Knee Osteoarthritis: A Randomized Clinical Trial.

In this study, the effects of an exercise therapy comprising yoga exercises and medial-thrust gait (YogaMT) on lower-extremity kinetics, pain, and function in patients with medial knee osteoarthritis were investigated. Fifty-nine patients were randomly allocated to three treatment groups: (a) the YogaMT group practiced yoga exercises and medial thrust gait, (b) the knee-strengthening group performed quadriceps- and hamstring-strengthening exercises, and (c) the treadmill walking group practiced normal treadmill walking in 12 supervised sessions. The adduction and flexion moments of the hip, knee, and ankle; pain intensity; and 2-min walking test were assessed before and after treatment and at 1-month follow-up. The YogaMT group experienced a significant reduction in knee adduction moment. All groups showed significant improvement in pain and function. The YogaMT may reduce medial knee load in patients with knee osteoarthritis in the short term. A larger clinical trial is required to investigate the long-term outcomes of this intervention.

Lower extremity kinematic analysis in male athletes with unilateral anterior cruciate reconstruction in a jump-landing task and its association with return to sport criteria.

BACKGROUND: Return to sport (RTS) criteria are widely being used to identify anterior cruciate ligament reconstructed (ACLR) athletes ready to return to sportive activity and reduce risk of ACL re-injury. However, studies show a high rate of ACL re-injury in athletes who passed RTS criteria. This indicates that the current RTS criteria might not be sufficient to determine return to sport time in ACLR athletes. Previous studies have reported a close association between altered lower limb kinematics and ACL re-injury. However, it is not clear how lower extremity kinematics differs between ACLR athletes who passed the RTS-criteria and who failed. This study compared lower extremity kinematics in a jump-landing task between ACLR athletes who passed the RTS criteria (Limb symmetry in hop tests, quadriceps strength and questionnaires) to those who failed and to the healthy individuals. METHODS: Participants were 27 male football players with unilateral ACLR including 14 who passed -RTS criteria and 13 failed, and 15 healthy football players. A 3D motion capture system recorded participants' lower extremity motion while performing 10 trials of a bilateral jump-landing task. Hip, knee and ankle angular motion were examined at initial contact. Two-way mixed analysis of variances (2 limbs × 3 groups) and Bonferroni post-hoc tests were performed to compare the joint angles between the limbs and groups. RESULTS: lower hip abduction angle was found in the failed (involved limb 4.1 ° ± 4.2) and passed RTS (involved limb 6.8° ± 3.3) groups compared to the healthy group (non-dominant limb 10.7° ± 3.7). Ankle inversion in the failed RTS (0.4° ± 4.9) group was significantly lower than both passed RTS (4.8° ± 4.8, p = 0.05) and healthy (8.2° ± 8.1, p < 0.001) groups. There were no significant differences between the groups in knee kinematics. CONCLUSIONS: Our findings indicate reduced hip abduction during initial contact phase of landing in athletes returned to sport. Reduced hip abduction during the complex multiplanar movement of jump-landing is a risk factor for ACL re-injury. Current RTS criteria may not be sufficient to identify ACLR athletes at high risk of re-injury. The kinematic analysis in conjunction with current RTS criteria can provide additional insight into the return to sport decision making.

Using Dual-Orthogonal Fluoroscopy and CT to Assess the Relationship Between Knee Morphology and Patellar Kinematics in Patients With Patellofemoral Pain.

INTRODUCTION: Patellofemoral pain (PFP) is one of the most common knee overuse injuries, with studies suggesting PFP as a precursor for early knee osteoarthritis. The etiology of PFP is multi-factorial; however, patellar mal-tracking has been regarded as a primary mechanism. Details of this multi-factorial mechanism have been unclear because of the limitations in evaluating in-vivo, three-dimensional (3D) patellofemoral joint movement during dynamic activities accurately. Alternatively, studies have demonstrated the high accuracy and repeatability of dual fluoroscopy and CT/MRI for measuring knee joint motion. OBJECTIVE: This study uses dual fluoroscopy and CT to investigate the associations between joint morphology and patellar kinematics in healthy controls and subjects with PFP. METHODS: Eight PFP females (29.7±10.6 years) and 10 healthy females (25.0±7.7 years) were recruited and screened by a sports medicine physician. CT imaging was performed on participants in a supine with the knee extended, and ankle and hip in neutral alignment. Dual-orthogonal fluoroscopy measured patellar movement while participants performed a lunge task. A calibration algorithm was used to register the 3D CT model to 2D fluoroscopy image to calculate the relative position and angles of the patella based on the clinical definition of patellar motion. Measures of patellar and trochlear morphology were generated and correlated to kinematic data. RESULTS AND CONCLUSION: There was a significant difference in the patellar-to-trochlear width ratio; however, no other significant differences in CT morphology measurements were present between groups. For PFP patients in the weight-bearing extended position, there was a moderate positive correlation between the patellar-to-trochlear width ratio and medial-lateral patellar shift (τ = 0.643, p = 0.026). Healthy controls in this position demonstrated a moderate positive correlation between the lateral-trochlear inclination angle and medial-lateral patellar shift (τ = 0.600, p = 0.016) and moderate negative correlation between medial trochlear inclination angle and medial-lateral patellar shift (τ = -0.511, p = 0.040). The findings suggest that, for this cohort, there is correlation between morphology and patellar kinematics. Passive and active stabilizers likely have a role in mal-tracking.

Brain Wave Patterns in Patients With Chronic Low Back Pain: A Case-control Study.

Introduction: Research evidence indicates that maladaptive reorganization of the brain plays a critical role in amplifying pain experiences and pain chronification; however, no clear evidence of change exists in brain wave activity among patients with chronic low back pain (CLBP). The objective of this study was to assess brain wave activity in patients with CLBP, compared to healthy controls. Methods: Twenty-five patients with CLBP and twenty-four healthy controls participated in the study. A quantitative electroencephalography device was used to assess brain wave activity in eyes-open and eyes-closed (EO and EC) conditions. The regional absolute and relative power of brain waves were compared between the groups. Results: Our results showed a significant increase in the absolute power of theta (F=5.905, P=0.019), alpha (F=5.404, P=0.024) waves in patients with CLBP compared to healthy subjects in both EC and EO conditions. Patients with CLBP showed a reduced delta absolute power in the frontal region (F=5.852, P=0.019) and augmented delta absolute power in the central region (F=5.597, P=0.022) in the EO condition. An increased delta absolute power was observed in the frontal (F=7.563 P=0.008), central (F=10.430, P=0.002), and parietal (F=4.596, P=0.037) regions in patients with CLBP compared to the healthy subjects in the EC condition. In the EC condition, significant increases in theta relative power (F=4.680, P=0.036) in the parietal region were also found in patients with CLBP. Conclusion: The increased absolute power of brain waves in people with CLBP may indicate cortical overactivity and changes in the pain processing mechanisms in these patients. Highlights: Chronic low back pain (CLBP) increases the alpha, theta, and delta power in the brain.CLBP is associated with increased brain wave activity in the frontal, central, and parietal regions.Our findings suggest altered central pain processing in CLBP. Plain Language Summary: Traditional diagnosis and treatment of CLBP are mainly focused on peripheral pathology. But, the modern neuroscience approach to pain highlights the role of cortical plasticity in chronic musculoskeletal pain. In this regard, several studies found structural and functional changes in the brain in patients with chronic pain. Detailed knowledge about cortical changes in CLBP can improve our understanding of mechanisms involved in CLBP, opening a new window to better treatment of LBP (Low back pain). This study investigated brain wave activity in patients with CLBP compared to healthy individuals. Our findings suggest increased brain activity in various parts of the brain in patients with chronic LBP. This finding indicates that CLBP treatment should focus on both peripheral and cortical factors rather than local tissue damage.

Can a rigid antipronation foot orthosis change the effects of prolonged standing on postural control in men with patellofemoral pain?

BACKGROUND: Pronated foot posture is known as a contributing factor for patellofemoral pain (PFP) development. Patients with patellofemoral pain often experience poor postural control. Implementation of optimal management strategies for enhancing their postural performance is important. OBJECTIVES: The aim of this study was to determine whether a rigid antipronation foot orthosis changes prolonged standing effects on postural control in men with PFP. STUDY DESIGN: Case-control study. METHODS: Twenty-eight men with PFP and pronated foot and 28 healthy men were enrolled in this study. Center-of-pressure parameters were measured during short trials (60 seconds) of single-leg standing before and immediately after prolonged standing (20 minutes) using force platform. In patients with PFP, postural control was examined on 2 separate days with and without rigid antipronation foot orthosis. RESULTS: Findings showed that the pre-post differences of sway area (t(48) = -2.22, p = 0.03), mediolateral (ML) displacement (t (48) = -2.51, p = 0.01), and mean velocity (t(48) = -2.01, p = 0.04) were significantly greater in patients with PFP without foot orthosis compared with those in the healthy group. Significant intervention main effect ( p = 0.04) and time-by-intervention interaction ( p = 0.006) for sway area were shown. Significant intervention main effects were noted for ML displacement ( p = 0.007) and mean velocity ( p = 0.003). For these variables, significant time-by-intervention interactions were found. Further analysis showed greater values of ML displacement and mean velocity parameters before the prolonged standing in patients with PFP without foot orthosis compared with patients with PFP with orthosis. CONCLUSIONS: Rigid antipronation foot orthosis can improve the postural performance after prolonged standing in young adult men with PFP.

Effects of Medial Thrust Gait on Lower Extremity Kinetics in Patients with Knee Osteoarthritis.

BACKGROUND: Medial thrust (MT) gait is a nonsurgical approach for reducing the knee adduction moment (KAM) in patients with knee osteoarthritis. However, its usefulness is indeterminate due to scarcity of research about changes in lower extremity kinetics and the ground reaction force (GRF) which have been investigated in this study. MATERIALS AND METHODS: Twenty patients (6 males, 14 females, age: 56.2±6.2 years) with medial knee osteo-arthritis participated in this cross-sectional study. A 12-camera motion analysis system and two force plates recorded kinematic and GRF data while participants walked barefoot along a 12m path with 1) their regular gait pattern and 2) MT gait pattern. The first peak adduction and flexion moments of the hip, knee, and ankle, and the sagittal and frontal GRF were measured. The center of pressure (CoP) location in the mediolateral direction at first KAM peak was also determined. RESULTS: MT gait significantly reduced the first KAM peak (mean difference= 169.7, p<0.001) and the hip flexion moment (mean difference: 82.6, p= 0.020) compared to normal gait. The mediolateral CoP significantly shifted laterally during MT gait compared to normal gait (mean difference: -12% foot width, p<0.001). There was no significant difference in other kinetics variables between the two gait patterns (p>0.05). CONCLUSIONS: 1. Our findings show that MT gait can reduce the KAM with no significant increase in the GRF and other lower extremity moments. 2. The results suggest that the reduced KAM associated with MT gait is caused by a lateral shift of the CoP, resulting in a reduced GRF moment arm.

Examination of Lumbopelvic and Lower Extremity Movements in two Subgroups of People with Chronic Low Back Pain Based on the Movement System Impairment Model During a Stair Descending Task.

BACKGROUND: Excessive and early lumbopelvic motion during functional tasks is associated with increased pain and symptoms in people with low back pain. The purpose of the current study was to compare lumbopelvic and lower extremity movements in two subgroups of chronic low back pain sufferers and healthy subjects during a stair descending task based on a movement system impairment model. MATERIAL AND METHODS: A clinical examination was conducted to assign people with low back pain to movement system impairment-based subgroups. A control group included 18 healthy subjects, a lumbar Rotation with Flexion group included 12 subjects, and a lumbar Rotation with Extension group included 16 subjects. Differences in kinematics data between the groups were recorded during a stair descending task using a 7-camera 3-dimensional motion capture system. RESULTS: In the lumbar Rotation with Flexion group, the onset of lumbar movement occurred earlier than in the control group (p = 0.043). In the lumbar Rotation with Flexion group, axial and frontal plane rotation of the pelvis and lower extremity were significantly greater than in the control group. Mean differences between the lumbar Rotation with Extension and control group were minimal for the motion assessed. CONCLUSION: Early and excessive lumbopelvic movement and more axial rotation in the lower extremities during a stair descending task were found in the lumbar Rotation with Flexion subgroup, which can be an important factor contributing to the development or persistence of low back pain in this group.

In-vivo patellar tracking in individuals with patellofemoral pain and healthy individuals.

Understanding of the exact cause of patellofemoral pain has been limited by methodological challenges to evaluate in-vivo joint motion. This study compared six degree-of-freedom patellar motion during a dynamic lunge task between individuals with patellofemoral pain and healthy individuals. Knee joints of eight females with patellofemoral pain and ten healthy females were imaged using a CT scanner in supine lying position, then by a dual-orthogonal fluoroscope while they performed a lunge. To quantify patellar motion, the three-dimensional models of the knee bones, reconstructed from CT scans, were registered on the fluoroscopy images using the Fluomotion registration software. At full knee extension, the patella was in a significantly laterally tilted (PFP: 11.77° ± 7.58° vs. healthy: 0.86° ± 4.90°; p = 0.002) and superiorly shifted (PFP: 17.49 ± 8.44 mm vs. healthy: 9.47 ± 6.16 mm, p = 0. 033) position in the patellofemoral pain group compared with the healthy group. There were also significant differences between the groups for patellar tilt at 45°, 60°, and 75° of knee flexion, and for superior-inferior shift of the patella at 30° flexion (p ≤ 0.031). In the non-weight-bearing knee extended position, the patella was in a significantly laterally tilted position in the patellofemoral pain group (7.44° ± 6.53°) compared with the healthy group (0.71° ± 4.99°). These findings suggest the critical role of passive and active patellar stabilizers as potential causative factors for patellar malalignment/maltracking. Future studies should investigate the associations between patellar kinematics with joint morphology, muscle activity, and tendon function in a same sample for a thorough understanding of the causes of patellofemoral pain. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

The effect of functional bracing on the arthrokinematics of anterior cruciate ligament injured knees during lunge exercise.

BACKGROUND: Functional knee braces are extensively used for partially and completely torn anterior cruciate ligament (ACL) patients and those who have undergone ACL graft reconstruction, in order to support the healing ACL, improve the joint's functional stability, and restore the normal joint kinematics. RESEARCH QUESTION: Does wearing braces alter the arthrokinematics of the ACL deficient knees during lung exercise? METHODS: For ten male unilateral ACL deficient subjects, 3D knee models were reconstructed from CT images, acquired in rest position. Sagittal plane fluoroscopy was then performed throughout a complete cycle of lunge in braced and non-braced conditions. The 3D kinematics of the knees were obtained using a 2D-3D registration method in which six anatomical bony landmarks on the fluoroscopic images were matched with those on the 3D models. RESULTS: No significant difference was found between the tibial anterior-posterior translations and abduction-adduction motions of the braced and non-braced knees. A significant decrease, however, was observed after bracing in the tibial internal rotation at 45° flexion during eccentric (non-braced: 5.9° (±6.7°) vs. braced: 2.4° (±7.0°); p = 0.045), and at 30° flexion during concentric (non-braced: 2.3° (±6.9°) vs. braced: -1.6° (±8.1°); p = 0.001) phases of the lunge cycle. SIGNIFICANCE: The immediate effect of knee bracing is limited to controlling the tibial rotation of the ACL deficient individuals during the lunge exercise. Hence, care should be taken in prescribing the lunge exercise for rehabilitation of ACL injured patients with high anterior-posterior knee instability, even when wearing knee braces.

Fluoroscopic Analysis of Tibial Translation in Anterior Cruciate Ligament Injured Knees With and Without Bracing During Forward Lunge.

BACKGROUND: Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. OBJECTIVES: In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee bracing on the sagittal plane kinematics of anterior cruciate ligament (ACL) injured patients. PATIENTS AND METHODS: For twelve male unilateral ACL deficient subjects, the anterior tibial translation was measured during lunge exercise in non-braced and braced conditions. Fluoroscopic images were acquired from the subjects using a digital fluoroscopy system with a rate of 10 fps. The image of each frame was scaled using a calibration coin and analyzed in AutoCAD environment. The angle between the two lines, tangent to the posterior cortexes of the femoral and tibial shafts was measured as the flexion angle. For the fluoroscopic images associated with 0°, 15°, 30°, 45° and 60° knee flexion angles, the relative anterior-posterior configuration of the tibiofemoral joint was assessed by measuring the position of landmarks on the tibia and femur. RESULTS: Results indicated that the overall anterior translations of the tibia during the eccentric (down) and concentric (up) phases of lunge exercise were 10.4 ± 1.7 mm and 9.0 ± 2.2 mm for non-braced, and 10.1 ± 3.4 mm and 7.4 ± 2.5 mm, for braced conditions, respectively. The difference of the tibial anterior-posterior translation behaviors of the braced and non-braced knees was not statistically significant. CONCLUSION: Fluoroscopic imaging provides an effective tool to measure the dynamic behavior of the knee joint in the sagittal plane and within the limitations of this study, the pure mechanical stabilizing effect of functional knee bracing is not sufficient to control the anterior tibial translation of the ACL deficient patients during lunge exercise.

Rehabilitation after ACL injury: a fluoroscopic study on the effects of type of exercise on the knee sagittal plane arthrokinematics.

A safe rehabilitation exercise for anterior cruciate ligament (ACL) injuries needs to be compatible with the normal knee arthrokinematics to avoid abnormal loading on the joint structures. The objective of this study was to measure the amount of the anterior tibial translation (ATT) of the ACL-deficient knees during selective open and closed kinetic chain exercises. The intact and injured knees of fourteen male subjects with unilateral ACL injury were imaged using uniplanar fluoroscopy, while the subjects performed forward lunge and unloaded/loaded open kinetic knee extension exercises. The ATTs were measured from fluoroscopic images, as the distance between the tibial and femoral reference points, at seven knee flexion angles, from 0° to 90°. No significant differences were found between the ATTs of the ACL-deficient and intact knees at all flexion angles during forward lunge and unloaded open kinetic knee extension (P < 0.05). During loaded open kinetic knee extension, however, the ATTs of the ACL deficient knees were significantly larger than those of the intact knees at 0° (P = 0.002) and 15° (P = 0.012). It was suggested that the forward lunge, as a weight-bearing closed kinetic chain exercise, provides a safer approach for developing muscle strength and functional stability in rehabilitation program of ACL-deficient knees, in comparison with open kinetic knee extension exercise.

Comparison of kinematics of ACL-deficient and healthy knees during passive flexion and isometric leg press.

BACKGROUND: Studying the kinematics of the ACL deficient (ACLD) knees, during different physiological activities and muscle contraction patterns, can improve our understanding of the joint's altered biomechanics due to ACL deficiency as well as the efficacy and safety of the rehabilitations exercises. METHODS: Twenty-five male volunteers, including 11 normal and 14 unilateral ACLD subjects, participated in this study. The kinematics of the injured knees of the ACLD subjects was compared with their intact knees and the healthy group during passive flexion and isometric leg press with the knees flexed from full extension to 45° flexion, with 15° intervals. An accurate registration algorithm was used to obtain the three dimensional kinematical parameters, from magnetic resonance images. RESULTS: The ACL deficiency mainly altered the tibial anterior translation, and to some extent its internal rotation, with the change in other parameters not significant. During leg press, the anterior translation of the ACLD knees was significantly larger than that of the normal knees at 30° flexion, but not at 45°. Comparison of the anterior translations of the ACLD knees during leg press with that of the passive flexion revealed improved consistency (CVs changed from 1.2 and 4.0 to 0.6 and 0.6, at 30° and 45° flexion, respectively), but considerable larger translations (means increased by 6.2 and 4.9mm, at 30° and 45° flexion, respectively). CONCLUSION: The simultaneous contraction of the quadriceps and hamstrings during leg press, although reduces the knee laxity, cannot compensate for the loss of the ACL to restore the normal kinematics of the joint, at least during early flexion.