Lower limb
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings in McMinn’s Concise Human Anatomy, 2017
Hip joint - the best example of a ball- and-socket joint. The head of the femur fits snugly into the acetabulum of the hip bone (Figs. 7.1, 7.8, 8.6), which is deepened around the periphery by the cartilaginous acetabular labrum and across the acetabular notch by the fibrous transverse acetabular ligament. The ligament of the head of the femur runs from the non-articular fossa close to the transverse ligament to the fovea of the head, carrying important blood vessels to the femoral head in the young child; however, these usually degenerate before adulthood. The capsule is attached to the hip bone around the margins of the acetabulum; on the femur, it attaches anteriorly to the intertrochanteric line, but posteriorly it attaches halfway along the neck. The capsule reflects back on itself towards the femoral head carrying the ret- inacular blood vessels that supply the femoral head in adults. Thus, much of the neck is intracapsular and covered by synovial membrane.
Fundamentals
Clare E. Milner in Functional Anatomy for Sport and Exercise, 2019
The shoulder is a ball and socket joint. The ball is the proximal end of the humerus, which sits in the shallow socket of the scapula known as the glenoid fossa (see shoulder complex – joints). This enables the shoulder to be extremely versatile in its movements and it is capable of multiaxial rotation (see planes and axes of movement). The humerus is held in place by strong ligaments and tendinous attachments. The elbow is a hinge joint formed by the articulation of the humerus and ulna and, therefore, has one main axis of rotation for flexion-extension (see elbow – joints). The articulation between the radius and the ulna is responsible for pronation and supination of the hand. With the elbow flexed to 90° from the anatomical position, the hand is in a supinated position when it is palm up and pronated when palm down. This movement is achieved by the radius crossing over the ulna in the forearm. The wrist lies between the ulna and radius and the metacarpal bones of the hand. The wrist joint is biaxial, permitting flexion-extension and abduction-adduction (see wrist and hand – joints).
Actions of Dopamine on the Skin and the Skeleton
Nira Ben-Jonathan in Dopamine, 2020
The adult human body contains 206 bones and approximately 300 joints, defined as points where two bones meet. Several types of joints are recognized. Synovial joints are found in arms and legs and enable bones to move over each other. Cartilaginous joints, such as those found in the spine and pelvis, provide more stability and less movement. Fibrous joints, as found in the skull, offer stability but do not allow movement at all in the adult. The joints between bones allow movement, with some allowing a wider range of movement than others, e.g., the ball and socket joint of the shoulder allows a greater range of movement than the pivot joint at the neck. Movement is powered by skeletal muscles, which are attached to the skeleton at various sites on bones.
Individual muscle contributions to hip joint-contact forces during walking in unilateral transfemoral amputees with osseointegrated prostheses
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Vahidreza Jafari Harandi, David Charles Ackland, Raneem Haddara, L. Eduardo Cofré Lizama, Mark Graf, Mary Pauline Galea, Peter Vee Sin Lee
A generic 10-segment, 23 degrees-of-freedom musculoskeletal model was scaled to the mass and anthropometry of each subject using OpenSim 3.2 (Delp et al. 2007). The head, arm and torso were lumped together as a single rigid body that articulated with the pelvis via a ball-and-socket back joint. The hip was modelled as a ball-and-socket joint, both anatomical knee and metatarsal joints of the intact limb as hinge joints, and each ankle-subtalar complex as a universal joint. The lower limbs and trunk were actuated by 76 Hill-type muscle-tendon units (Zajac 1989) (see Supporting Information). A scaling factor was calculated using the relative distance between each segment’s pair of markers measured in a static standing calibration trial, and the corresponding virtual markers mounted in the model (Delp et al. 2007; Schache et al. 2018). Scaled-personalized models of each subject were created by scaling segment lengths and muscle tendon parameters of the generic musculoskeletal model (Dorn 2011).
EFab domain substitution as a solution to the light-chain pairing problem of bispecific antibodies
Published in mAbs, 2018
Heather A. Cooke, Joe Arndt, Chao Quan, Renée I. Shapiro, Dingyi Wen, Susan Foley, Malgorzata M. Vecchi, Martin Preyer
Substitution of the EFab led to a decrease in thermal stability of the Fabs as measured by DSC. A series of trastuzumab constructs were produced containing various linkers, including the linker from the Cɛ2, which was engineered onto the light chain, as well as GlySer linkers on both the light and heavy chains. These constructs exhibited slightly decreased thermal stability, indicating that linker length and flexibility are not critical parameters for improving stability and that the native linker from the starting antibody may be best. Nevertheless, based on what was observed from the structure of adalimumab EFab, it may be necessary to engineer an even longer linker on the heavy chain to increase the angle of the elbow region to relieve the clashing at the interface of VH and Cɛ2. The high amount of disorder as indicated by the high B-factors of this region may be a result of this steric clashing or may be inherent to the interaction of the two domains. In the elbow region of a Fab, the variable and constant domains meet to form a tightly associated molecular ball-and-socket joint.23 Mutations in this region distal from the antigen-binding site have been shown to negatively affect thermo-stability, binding affinity, and bispecific activity by modulating the interdomain conformational dynamics.24,25 In spite of the structural effects of EFab domain substitution, the monovalent binding kinetics of adalimumab EFab was only two-fold worse than adalimumab to its antigen, human TNF.
Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Michael A. Samaan, Stacie I. Ringleb, Sebastian Y. Bawab, Eric K. Greska, Joshua T. Weinhandl
An eight segment, 24 degree of freedom (DOF) model, modified from a previously published musculoskeletal model (Rajagopal et al. 2016), was used to perform the musculoskeletal simulations of the SEBT and SLH tasks. Musculoskeletal simulations of the SEBT and SLH trials were performed using OpenSim (v3.3) (Delp et al. 2007).The torso segment was modeled as a ball and socket joint and consisted of three DOFs. The pelvis segment was modeled with three translational and three rotational DOFs. The hip joints were each modeled as a ball and socket joint and consisted of three DOFs each. Each knee joint was modified to include three DOFs (i.e. flexion/extension, abduction/adduction, rotation) (Mokhtarzadeh et al. 2014; Weinhandl et al. 2014; Weinhandl and O’Connor 2010). The patella joint articulated with the femur and patellar kinematics were estimated using the knee flexion angle (Arnold et al. 2010). Tibiofemoral translations were expressed as a function of knee flexion angle (Yamaguchi and Zajac 1989). The ankle joints were each modeled using one DOF. The lower extremities were actuated using 80 musculotendon units (40 units per leg) (Millard et al. 2013). Static optimization (SO) was used to estimate muscle forces at each time instant during the SEBT and SLH trials by decomposing the net joint moments into individual muscle forces through a minimization of the sum of the muscle activations squared (Anderson and Pandy 2001).
Related Knowledge Centers
- Acetabulum
- Shoulder Joint
- Sternoclavicular Joint
- Synovial Joint
- Femoral Head
- Pelvis
- Scapula
- Humerus
- Hip
- Glenoid Fossa