Rotation, biomechanical

Chao, E. Y.S. 1980. justification of triaxial goniometer for the measurement of joint rotation. Biomechanics, 13 989-1006. 

Biomechanics considers safety and health implications of mechanics, or the study of the action of forces, for the human body (its anatomical and physiological properties) in motion (at work) and at rest Mechanics, which is based on Newtonian physics, consists of two main areas statics or the study of the human body at rest or in equilibrium, and dynamics or the study of the human body in motion. Dynamics is further subdivided into two main parts, kinematics and kinetics. Kinematics is concerned with the geometry of motion, including the relationships among displacements, velocities, and accelerations in both translational and rotational movements, without regard to the forces involved. Kinetics, on the other hand, is concerned with forces that act to produce the movements. 

The prosthesis for total knee joint replacement consists of femoral, tibial, and patellar components. Compared to the hip joint, the knee joint has a more complicated geometry and movement biomechanics, and it is not intrinsically stable. In a normal knee, the center of movement is controlled by the geometry of the ligaments. As the knee moves, the ligaments rotate on their bony attachments and the center of movement also moves. The eccentric movement of the knee helps distribute the load throughout the entire joint surface [Burstein and Wright, 1993]. 

Amis AA, Bull AMI and Lie DTT. Biomechanics of rotational instabhity and anatomic anterior cruciate hgament reconstruction. Operat Tech Orthop. 2005 15 29-35. 

For ACL reconstruction, some have created femoral tuimels in the direct attachment of the midsubstance fibers [2, 12], whereas others have recommended that they should include as much as the whole area including the attachment of the fanlike extensimi fibers [13, 14]. This discrepancy can occur due to our lack of knowledge on the transmission of the load carried by the ACL to the femoral attachment, fri some biomechanical studies in which the ACL was separated into 2 fiber bundles [15] or 3 fiber bundles [16], however, those did not use recent anatomic knowledge of the ACL attachment. The purpose of the second study was to clarify the load-bearing functions of the fibers of the femoral anterior cruciate ligament (ACL) attachment in the resistance of tibial anterior drawer and rotation. 

Previously, anatomical studies have been performed to know the position of the anatomical anterior cruciate ligament (ACL) insertion [1-18], and the ACL can be divided into two parts the anteromedial (AM) and posterolateral (PL) bundles [1], These bundles have different functimis with different lengths and force-change patterns [19-21], and some biomechanical studies described that anatomical double-bundle (DB) ACL reconstruction achieved equal knee kinematics to those of the intact knee with stability of tibial anterior translation and rotation [22-24]. As a result, anatomical DB ACL reconstruction is a widely used procedure. Femoral... 

The primary motion of the knee joint is flexion-extension rotation around an axis passing through the medial and lateral femoral condyles. The three-dimensional motions of the knee other than flexion-extension rotation are constrained by ligaments, menisci, and articular surface configuration. The biomechanical functions of the ACL are mainly to resist anterior tibial translation, and secondly to resist internal and valgus tibial rotation, or combined motions. 

Fukubayashi T, Torzilli PA, Sherman MF, Warren RF (1982) An in vitro biomechanical evaluation of anterior-posterior motion of the knee. Tibial displacement, rotation, and torque. J Bone Joint Surg Am 64 258-264... 

Yasuda K, Ichiyama H, Kondo E, Miyatake S, Inoue M, Tanabe Y (2008) An in vivo biomechanical study on the tension-versus-knee fleximi angle curves of two grafts in anatomic double-bundle anterior cruciate ligament reconstruction effects of initial tension and internal tibial rotation. Arthroscopy 24 276-284... 

Maeyama A, Hoshino Y, Debandi A, Kato Y, Saeki K, Asai S, Goto B, Smolinski P, Fu FH (2011) Evaluation of rotational instability in the anterior cruciate ligament deficient knee using triaxial accelerometer a biomechanical model in porcine knees. Knee Surg Sports Traumatol Arthrosc 19 1233-1238... 

Recently, on the basis of several biomechanical studies [41, 65], double-bundle ACL reconstmction, which is designed to reproduce both the anteromedial bundle (AMB) and the posterolateral bundle (PLB), became increasingly popular over the past decade, because this procedure was able to more closely restore the rotational stability compared with the conventional single-bundle technique [2]. Siebold... 

Kondo et al. [4] reported a unique laboratory study to verify biomechanical effects of this ACL reconstruction procedure. Namely, they arthroscopically performed this anatomic double-bundle reconstruction procedure and the conventional single-bundle reconstruction procedure with cadaver knees and biomechan-ically compared the knee stability among the two procedures and the normal knee, under the following loading conditions 90-N anterior tibial force, 5-Nm internal and external tibial torques, and a simulated pivot-shift test. In the results, there were significant reductions of anterior laxity of 3.5 mm and internal rotational laxity of... 

An external load test was conducted to compare the biomechanical behavior of the rectangular tunnel ACL-reconstructed knee with that of the round tunnel ACL-reconstructed knee (Fig. 31.4). The mean anterior laxity of rectangular tunnel ACL-reconstructed knees at 30° flexion with 5 Nm of internal rotation and 10 Nm of valgus moment load was 0.4 mm greater than that of the normal knee, whereas the mean anterior laxity of the round tunnel ACL-reconstructed knees under the same conditions was 0.8 mm greater than that of the normal knee. 

Nakamae et al. also evaluated the biomechanical function of ACL remnants using a navigation system for anteroposterior and rotational knee stability in patients with a complete ACL injury [24]. Patients in groups 1 (bridging between the posterior cruciate ligament and tibia) and 2 (bridging between the intercondylar... 

Kinematics of the Lumbosacral Junction. The second major biomechanical fundamental of the spine is to allow movement. The study of rigid body movement is kinematics. It is important to realize that as a vertebra moves from one position to the next, this motion can be described in a variety of ways. By assuming the vertebra is a rigid body, we may describe its motion in terms of rotation and translation. Note that translation is dependent upon which point on the vertebra is selected. In two dimensions, the... 

Pang D, Li V (2004) Atlantoaxial rotatory fixation Part 1 - Biomechanics of normal rotation at the atlantoaxial joint in children. Neurosurgery 55 614-625 discussion 625-626... 

Three-dimensional reconstructions of CT and MR images can delineate precisely the spatial relationship between bones and musculotendinous structures and produce a good 3D visual presentation of biodynamic events of human joints. Rotational motion of a shoulder, knee flexion, other complex musculoskeletal motions and muscle contraction (Fig. 24.15) can be assessed, as well as the effect of muscle dysfunction and its relevance to the mechanics of joints (Totterman et al. 1998). This method is of great interest because many biomechanical studies are based on dramatically simplified anatomic models. 

Engineering thermoplastics possess better dynamic mechanical properties than other thermoplastics. They have current or potential apphca-tions for gears, valves, rotating blades, biomechanicals such as prosthetics and orthopedic implants, springs, pumps, thin film membranes, transmission components, and small-amphtude vibration step-loading apph-cations [3]. 

Newton s laws describe the conservation of energy and the state of equilibrium. Equilibrium results when the sum of forces is zero and no change occurs, and conservation of energy explains that energy cannot be created or destroyed, only converted from one form to another. Motion occurs in two ways, linear motion in a particular direction or rotational movement around an axis. Biomechanics explores and quantifies the movement and production of force used or required to produce a desired objective. 

Chang, C. H., Chen, C. H., Su, C. Y., Liu, H. T., and Yu, C. M. 2009. Rotator cuff repair with periosteum for enhancing tendon-bone healing A biomechanical and histological study in rabbits. Knee. Surg. Sports Traumatol. Arthrosc. 17 1447-1453. 

Derwin, K. A., Baker, A. R., Spragg, R. K., Leigh, D. R., and lannotti, J. P. 2006. Commercial extracellular matrix scaffolds for rotator cuff tendon repair. Biomechanical, biochemical, and cellular properties. J. Bone Joint Surg. Am. 88 2665-2672. 

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