The movement systems: skeletal and muscular
Nick Draper, Helen Marshall in Exercise Physiology, 2014
A detailed illustration of the knee joint, the most complex joint in the body, is provided in Figure 5.7. The knee is in fact made up of three joints or articulations. One joint is formed between the patella and the femur and the other two are formed at the junctions of the lateral condyle and the medial condyle of the femur with the tibia. To facilitate smooth articulation, the condyles of the femur articulate on a combination of the lateral and medial menisci (fibrocartilage) of the tibia and the tibial articular cartilage (hyaline cartilage). The joint is held together by a complex arrangement of intracapsular and extracapsular ligaments and tendons. The anterior and posterior cruciate ligaments, which are contained within the synovial capsule, protect against forward and backward displacement of the tibia in relation to the femur, respectively. Outside the capsule and posterior to it, the joint is held together by the popliteal ligaments and the attachment of several muscles to the tibia and femur. On the anterior surface of the knee the quadriceps tendon, which encloses the patella, attaches to the tibia to further strengthen the joint. To the sides of the joint the tibial (medial) and fibular (lateral) collateral ligaments protect against over rotation about the joint. Within the joint, around a dozen bursae (synovial-fluid-filled sacs) and fat pads provide further structural support and cushioning for the joint and help to further decrease friction between the bones. Together these structures enable flexion, extension and limited rotation.
Hip and knee
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie in Bailey & Love's Short Practice of Surgery, 2018
Knee problems, in the case of injury, can present acutely or some time after the event (see Chapter 32). Problems can be associated with degenerative changes, in which case a more chronic presentation can be encountered. Specific structures commonly involved are the ligaments, tendons and menisci. Ligamentous injuries may involve the cruciate and collateral ligaments and can be combined with injury to stabilising structures, e.g. the posterolateral corner. Tendon problems include injuries to the quadriceps tendon and the patellar tendon. The pattern of meniscal injury or degeneration is variable, affecting either the medial or lateral meniscus (or both). There are several patterns of injury within a meniscal structure, some relating to blood supply and healing potential. Furthermore, soft tissue problems can be associated with chondral or osteochondral lesions.
The knee
Ashley W. Blom, David Warwick, Michael R. Whitehouse in Apley and Solomon’s System of Orthopaedics and Trauma, 2017
The quadriceps tendon is inserted into the upper pole of the patella. It is in line with the shaft of the femur, whereas the patellar tendon is in line with the shaft of the tibia. Because of the angle between them (the Q-angle) quadriceps contraction would pull the patella laterally were it not for the fibres of vastus medialis, which are transverse. This muscle is therefore important and it is essential to try to prevent the otherwise rapid wasting that is liable to follow any effusion.
Patellofemoral cartilage stresses are most sensitive to variations in vastus medialis muscle forces
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Saikat Pal, Thor F. Besier, Garry E. Gold, Michael Fredericson, Scott L. Delp, Gary S. Beaupre
We applied the quadriceps muscle forces to our FE models to estimate cartilage stresses corresponding to 60° knee flexion during a stair climb task. Quasi-static, finite-sliding analyses were performed using a non-linear FE solver (ABAQUS Explicit, SIMULIA, Providence, RI). The patella was kinematically unconstrained in all six degrees of freedom, while the tibia and femur were constrained in all six degrees of freedom. The individual quadriceps muscle forces were applied to the respective components of the quadriceps tendon connector elements, and the patella was allowed to settle into its lowest energy state in the trochlear groove. We quantified cartilage stress using an energy-based effective stress, a scalar quantity representing the local stress intensity in the tissue (Beaupre et al. 1990; Carter and Beaupre 2001). Effective stress is given by:
The effect of rectus femoris muscle modelling technique on knee joint kinematics: a preliminary study
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
E. Elyasi, A. Perrier, Y. Payan
The bones were modeled as rigid bodies. All the constraining ligaments including the patellar ligament, the lateral and medial patellar retinaculum ligaments, the collateral and cruciate ligaments and the anterolateral ligament were modeled as 1 D linear spring elements having 150 N/mm stiffness (Woo et al. 1991). The hamstring muscle group was modelled as 1 D while conserving the muscles’ anatomical moment arms. The 3 D active muscles consist of an active part using the Blemker constitutive model (Blemker et al. 2005) and a passive part considered to be neo-Hookean hyperelastic (Luboz et al. 2018) Muscle fibers are distributed along the length of the muscle in the direction of the vector connecting the muscle insertion sites. The quadriceps tendon attached to the 3 D rectus Femoris muscle was modeled as multipoint springs being able to wrap around the femur bone (Figure 1).
Modification of a sonographic enthesitis score to differentiate between psoriatic arthritis and young healthy volunteers
Published in Scandinavian Journal of Rheumatology, 2018
K Wervers, M Vis, N Rasappu, M van der Ven, I Tchetverikov, MR Kok, AH Gerards, JMW Hazes, JJ Luime
The majority of patients and half of the healthy volunteers had a PD signal present in at least one enthesis (Table 3). A PD score of 2 or more in at least one enthesis was present in 52% of new and 44% of established PsA patients and in 28% of healthy volunteers. The lateral epicondyle and the quadriceps tendon were affected in one-third of the entheses in patients (Table 2). In healthy volunteers, one-third of the quadriceps entheses and distal patellar entheses showed a PD signal.
Related Knowledge Centers
- Patellofemoral Pain Syndrome
- Patella
- Body
- Quadriceps
- Tuberosity of The Tibia
- Patellar Tendon
- Quadriceps Tendon Rupture