Virtual Axis Finder: A New Method to Determine the Two Kinematic Axes of Rotation for the Tibio-Femoral Joint

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Michelle Roland ◽  
M. L. Hull ◽  
S. M. Howell

The tibio-femoral joint has been mechanically approximated with two fixed kinematic axes of rotation, the longitudinal rotational (LR) axis in the tibia and the flexion-extension (FE) axis in the femur. The mechanical axis finder developed by Hollister et al. (1993, “The Axes of Rotation of the Knee,” Clin. Orthop. Relat. Res., 290, pp. 259–268) identified the two fixed axes but the visual-based alignment introduced errors in the method. Therefore, the objectives were to develop and validate a new axis finding method to identify the LR and FE axes which improves on the error of the mechanical axis finder. The virtual axis finder retained the concepts of the mechanical axis finder but utilized a mathematical optimization to identify the axes. Thus, the axes are identified in a two-step process: First, the LR axis is identified from pure internal-external rotation of the tibia and the FE axis is identified after the LR axis is known. The validation used virtual simulations of 3D video-based motion analysis to create relative motion between the femur and tibia during pure internal-external rotation, and flexion-extension with coupled internal-external rotation. The simulations modeled tibio-femoral joint kinematics and incorporated 1 mm of random measurement error. The root mean squared errors (RMSEs) in identifying the position and orientation of the LR and FE axes with the virtual axis finder were 0.45 mm and 0.20 deg, and 0.11 mm and 0.20 deg, respectively. These errors are at least two times better in position and seven times better in orientation than those of the mechanical axis finder. Variables, which were considered a potential source of variation between joints and/or measurement systems, were tested for their sensitivity to the RMSE of identifying the axes. Changes in either the position or orientation of a rotational axis resulted in high sensitivity to translational RMSE (6.8 mm of RMSE per mm of translation) and rotational RMSE (1.38 deg of RMSE per degree of rotation), respectively. Notwithstanding these high sensitivities, corresponding errors can be reduced by segmenting the range of motion into regions where changes in either position or orientation are small. The virtual axis finder successfully increased the accuracy of the mechanical axis finder when the axes of motion are fixed with respect to the bones, but must be used judiciously in applications which do not have fixed axes of rotation.

Author(s):  
Michelle Roland ◽  
Maury L. Hull ◽  
Stephen M. Howell

Kinematic modeling of the knee requires an accurate method to identify the rotational axes [1]. The tibio-femoral joint has two fixed rotational axes: the flexion-extension axis in the femur (FE) and the longitudinal rotational axis in the tibia (LR) [2–4]. Because the knee naturally produces coupled rotation about the LR axis during flexion, attempting to identify the axes from natural flexion alone creates an underdetermined system. A previous study using a mechanical axis finder identified the FE and LR axes by initially identifying the LR axis from pure internal-external (I/E) rotations [4]. Because the major source of error in this method was the visually-based alignment of the axis finder, it should become more repeatable and reliable by utilizing a mathematical optimization to situate the axis finder. Therefore, the two objectives were to develop and validate a new axis finding method, which is based on a mathematical optimization, for identifying the two fixed rotational axes of the tibio-femoral joint.


2019 ◽  
pp. 121-131

Introduction: Breast cancer is the most common type of cancer among women in Brazil and in the worl. The surgical treatment procedure may cause severe morbidity in the upper limb homolateral to surgery, including the reduction of the range of motion, with consequent impairment of function. A physiotherapeutic approach has an important role in the recover range of motion and the functionality of these women, guaranteeing the occupational, domestestic, familiar and conjugated activities, and, in this way, also improving the quality of life. Objectives: To analyse chances in the shoulder's range of motion and the functional capacity of the upper limbs, promoted by the deep running procedure in women with late postoperative mastectomy. Methods: All the patients were submitted to an evaluation in the beginning and end of the treatment, including: goniometry of flexion, extension, abduction, adduction, internal and external rotation of the shoulder joint; and function capacity analysis in activities that involve the upper members by DASH questionnaire. The treatment protocol includes twelve sessions of deep running, realized twice a week, in deep pool, for 20-minute during six weeks. Results: Were submitted to treatment a total of 4 patients. Despite the improvement in the numerical values, statistically significant differences were not found on the range of movements and in the functional capacity of upper members before and after the deep running sessions in post-mastectomy women. Conclusion: Deep running had effects on the numerical values of range of movement and upper limb functionality in women in the late postoperative period of the mastectomy procedure, but without statistically significant differences.


2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.


2021 ◽  
pp. 1-6
Author(s):  
Young Jin Jo ◽  
Young Kyun Kim

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.


2012 ◽  
Vol 38 (3) ◽  
pp. 237-241 ◽  
Author(s):  
J. A. Bertelli ◽  
M. F. Ghizoni

Stretch injuries of the C5-C7 roots of the brachial plexus traditionally have been associated with palsies of shoulder abduction/external rotation, elbow flexion/extension, and wrist, thumb, and finger extension. Based on current myotome maps we hypothesized that, as far as motion is concerned, palsies involving C5-C6 and C5-C7 root injuries should be similar. In 38 patients with upper-type palsies of the brachial plexus, we examined for correlations between clinical findings and root injury level, as documented by CT tomomyeloscan. Contrary to commonly held beliefs, C5-C7 root injuries were not associated with loss of extension of the elbow, wrist, thumb, or fingers, but residual hand strength was much lower with C5-C7 vs C5-C6 lesions.


2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Dongquan Shi ◽  
Xingquan Xu ◽  
Anyun Guo ◽  
Jin Dai ◽  
Zhihong Xu ◽  
...  

Introduction. Mechanical alignment deviation after total knee arthroplasty is a major reason for early loosening of the prosthesis. Achieving optimum cement penetration during fixation of the femoral and tibial component is an essential step in performing a successful total knee arthroplasty. Bone cement is used to solidify the bone and prosthesis. Thickness imbalance of bone cement leads to the deviation of mechanical alignment. To estimate the influence of bone cement, a retrospective study was conducted.Materials and Methods. A total of 36 subjects were studied. All the TKA were performed following the standard surgical protocol for navigated surgery by medial approach with general anaesthesia. Prostheses were fixed by bone cement.Results. We compared the mechanical axis, flexion/extension, and gap balance before and after cementation. All the factors were different compared with those before and after cementation. Internal rotation was reached with statistical significance (P=0.03).Conclusion. Bone cement can influence the mechanical axis, flexion/extension, and gap balance. It also can prompt us to make a change when poor knee kinematics were detected before cementation.


Author(s):  
Imran M. Omar

Chapter 107 discusses the hip and its component tissues, including the bones, labrum, synovial tissues, muscles, and tendons, and covers the MRI appearances of many of the most common pathologies that occur in and around the hip joint. The hip is a ball-and-socket joint consisting of the femoral head and the cup-shaped acetabulum. Because of its shape, the hip allows multi-axial movements, including flexion/extension, abduction/adduction, and internal/external rotation. A number of supporting structures, including the acetabular labrum and joint capsule, surrounding muscles and tendons, and bursae, help stabilize the hip and allow for a smooth range of motion. Injuries to any of these structures can result in hip pain and loss of function. MRI has become the test of choice to assess hip internal derangement because of its superior assessment of soft tissues and bone marrow and its contrast resolution, which improves conspicuity of pathologic conditions.


2017 ◽  
Vol 31 (01) ◽  
pp. 068-074
Author(s):  
Swithin Razu ◽  
Keiichi Kuroki ◽  
James Cook ◽  
Trent Guess

AbstractThe function and importance of the anterior intermeniscal ligament (AIML) of the knee are not fully known. The purpose of this study was to evaluate the biomechanical and sensorimotor function of the AIML. Computational analysis was used to assess AIML and tibiomeniscofemoral biomechanics under combined translational and rotational loading applied during dynamic knee flexion–extension. Histologic and immunohistochemical examination was used to identify and characterize neural elements in the tissue. The computational models were created from anatomy and passive motion of two female subjects and histologic examinations were conducted on AIMLs retrieved from 10 fresh-frozen cadaveric knees. It was found that AIML strain increased with compressive knee loading and that external rotation of the tibia unloads the AIML, suppressing the relationship between AIML strain and compressive knee loads. Extensive neural elements were located throughout the AIML tissue and these elements were distributed across the three AIML anatomical types. The AIMLs have a beneficial influence on knee biomechanics with decreased meniscal load sharing with AIML loss. The AIML plays a significant biomechanical and neurologic role in the sensorimotor functions of the knee. The major role for the AIML may primarily involve its neurologic function.


2020 ◽  
Vol 8 (12) ◽  
pp. 232596712096629
Author(s):  
Caroline Martin ◽  
Anthony Sorel ◽  
Pierre Touzard ◽  
Benoit Bideau ◽  
Ronan Gaborit ◽  
...  

Background: The open stance forehand has been hypothesized by tennis experts (coaches, scientists, and clinicians) to be more traumatic than the neutral stance forehand as regards hip injuries in tennis. However, the influence of the forehand stance (open or neutral) on hip kinematics and loading has not been assessed. Purpose: To compare the kinematics and kinetics at the hip joint during 3 common forehand stances (attacking neutral stance [ANS], attacking open stance [AOS], defensive open stance [DOS]) in advanced tennis players to determine whether the open stance forehand induces higher hip loading. Study Design: Descriptive laboratory study. Methods: The ANS, AOS, and DOS forehand strokes of 8 advanced right-handed tennis players were recorded with an optoelectronic motion capture system. The flexion-extension, abduction-adduction, and external-internal rotation angles as well as intersegmental forces and torques of the right hip were calculated using inverse dynamics. Results: The DOS demonstrated significantly higher values than both the ANS and AOS for anterior ( P < .001), medial ( P < .001), and distractive ( P < .001) forces as well as extension ( P = .004), abduction ( P < .001), and external rotation ( P < .001) torques. The AOS showed higher distractive forces than the ANS ( P = .048). The DOS showed more extreme angles of hip flexion ( P < .001), abduction ( P < .001), and external rotation ( P = .010). Conclusion: The findings of this study imply that the DOS increased hip joint angles and loading, thus potentially increasing the risk of hip overuse injuries. The DOS-induced hip motion could put players at a higher risk of posterior-superior hip impingement compared with the ANS and AOS. Clinical Relevance: Coaches and clinicians with players who have experienced hip pain or sustained injuries should encourage them to use a more neutral stance and develop a more aggressive playing style to avoid the DOS, during which hip motion and loading are more extreme.


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