FREE Master of Occupational Therapy Kinesiology Questions and Answers
When the teeth are clenched or when the mouth is slightly open, is the TMJ (jaw) in the close-packed position?
The temporomandibular joint (TMJ) is in the close-packed position when the teeth are clenched. The TMJ is a complex joint that connects the mandible (lower jaw) to the temporal bone of the skull. It allows for various movements of the jaw, including opening and closing the mouth, moving the jaw side to side, and allowing for chewing and speaking. The close-packed position of a joint is the position where the joint surfaces have the maximum contact and are most stable. In the case of the TMJ, when the teeth are clenched together, the joint is in its close-packed position. This position provides stability and support to the joint, allowing for increased force transmission during activities such as biting and chewing.
In an extended position, flex the shoulder and check to see if the scapula's glenoid fossa has a concave or convex joint surface.
The glenoid fossa is concave, meaning it has a curved surface that faces inward. This concave shape allows it to articulate with the head of the humerus (the upper arm bone), which has a corresponding convex surface. The combination of the concave glenoid fossa and the convex head of the humerus creates a highly mobile joint that allows for a wide range of shoulder movements, including flexion, extension, abduction, adduction, and rotation.
Laterally, but a little lower to the greater side of the angle
The resultant force of the sternal and clavicular portions of the pectoralis major forms an upward and lateral force vector, creating a "V" or ">" shape. The pectoralis major is a large muscle located in the chest area. It consists of two portions: the sternal portion and the clavicular portion. The sternal portion originates from the sternum (breastbone), while the clavicular portion originates from the clavicle (collarbone). When both portions contract simultaneously, the muscle fibers of the pectoralis major pull towards the center of the body, resulting in a force that is directed upwards and laterally. This upward and lateral force vector creates the ">" or "V" shape of the muscle as it converges towards the attachment point on the humerus (upper arm bone).
What trunk joint motion is involved in picking up a pencil from the floor next to your chair?
Lateral bending of the trunk refers to the side-to-side movement of the spine, where the upper body bends towards one side while the opposite side lengthens. When you reach down to pick up a pencil from the floor beside your chair, you may perform lateral bending to the side where the pencil is located. This motion helps you reach the object without having to twist your spine excessively.
Lateral (external)
When you put your right ankle on your left knee, your right hip is externally rotated. The right thigh bone (femur) is rotated outward, away from the midline of the body, allowing the right ankle to rest on the left knee. This position is commonly used in exercises or yoga poses to stretch the hips and glutes and improve hip flexibility.
Traction (distraction)
Traction (distraction) is an accessory motion that involves the separation of joint surfaces in the longitudinal direction, away from each other. In the context of swinging a child around by her arms, the force applied to the child's arms causes a traction or distraction force at the shoulder joints. This force pulls the head of the humerus (upper arm bone) away from the glenoid cavity of the scapula (shoulder blade), resulting in a separation of the joint surfaces.
What kind of force is exerted to the front section of the vertebra when a person squats down to touch the ground in the sagittal plane?
Compression force is a type of force that acts in the direction of reducing the space or compressing the structures involved. In the context of bending down, the weight of the upper body exerts a downward force on the vertebral column. This force compresses the anterior part of the vertebrae, meaning it pushes the front portions of the vertebrae closer together.
Where is hyaline cartilage found?
Hyaline cartilage is a crucial type of cartilage that provides structural support, flexibility, and smooth articulating surfaces in various parts of the body. Its unique properties make it well-suited for its specific roles in different anatomical locations.
Make pencil marks on 25 cents at 6:00 and 12:00. Flatten the $5 bill out. Which arthorkinematic motion will you need to make in order to reach the end of the flat 5 by 12:00 if you roll the 25 across it starting from the 6:00 position with the edge of the 25?
Arthrokinematics refers to the movement that occurs between the articulating surfaces of joints. In this case, the joint involved is the point of contact between the 25¢ and the 5¢ piece as the 25¢ rolls across the flat surface of the 5¢. When the 25¢ rolls across the flat 5¢, the movement at the joint is primarily a glide or slide. The rolling motion of the 25¢ involves translation or gliding of the contacting surfaces along each other, allowing the 25¢ to move from the 6:00 position to the 12:00 position on the 5¢. Glide or slide is one of the basic types of arthrokinematic motions and is common in various joint movements. In this context, it allows the 25¢ to smoothly move along the surface of the flat 5¢ piece, resulting in its position change from the 6:00 to the 12:00 position.
Concave
When placing two Pringles chips at opposite angles (Fig 13-2), the A/P (Anterior/Posterior) shape of the top surface of the bottom chip is "Concave," while the bottom surface of the top chip is "Convex." The concave surface curves inward, resembling the shape of the inside of a bowl, while the convex surface curves outward, resembling the shape of the outside of a bowl. This unique shape pairing allows the chips to fit together snugly, similar to how certain joint surfaces in the human body fit together in synovial joints. In the human body, joints often have articulating surfaces with one being concave and the other being convex. This arrangement provides stability, mobility, and efficient load transmission within the joint, allowing for smooth and controlled movement.
Long bones have cancellous bone in the metaphysis and epiphysis but compact bone in the diaphysis. (Also discovered between compact bone's layers)
One example of cancellous bone is the epiphysis of long bones, such as the ends of the femur. The epiphysis contains a higher proportion of cancellous bone, which has a spongy, lattice-like structure with many small trabeculae. Cancellous bone in the epiphysis helps to reduce the weight of the bone while still providing structural support and a site for red bone marrow, where blood cells are produced.
Joint Capsule
The joint capsule serves as a protective barrier around the joint, helping to maintain the joint's structural integrity and supporting its function. It is one of the essential components of a synovial joint, which is the most common type of joint in the body and allows for a wide range of movements. The joint capsule works in conjunction with other structures, such as ligaments, tendons, and cartilage, to provide stability and flexibility to the joint.
Flex the shoulder from an extended posture and check to see if the humerus is moving on the scapula or the other way around.
When flexing the shoulder from an extended position, the movement involves the humerus moving on the glenoid cavity of the scapula. The shoulder joint is a ball-and-socket joint, and the flexion motion allows for raising the arm forward and upward. Muscles such as the anterior deltoid, pectoralis major, and coracobrachialis work together to facilitate this movement. Flexing the shoulder is essential for various activities, including reaching, lifting objects, and performing overhead movements.
Which is heavier, cancellous bone or compact bone? Then why?
The correct answer is A. Compact bone is heavier than cancellous (also known as trabecular or spongy) bone. Compact bone, also called cortical bone, forms the outer layer of most bones and is denser and stronger compared to cancellous bone. It consists of tightly packed layers of bone tissue with few spaces between them. The dense nature of compact bone provides strength and support to the bone, making it more resistant to bending and torsion. Cancellous bone, on the other hand, forms the inner layer of most bones and has a spongy, lattice-like structure. It contains a network of trabeculae, which are small, thin, and interconnected bone struts. Cancellous bone is less dense and more porous compared to compact bone, making it lighter in weight.
Thumb CMCJ
The Carpometacarpal Joint (CMCJ) of the thumb is diarthrodial, synovial, biaxial, and saddle in nature, which allows for its unique and extensive range of movements, contributing to the thumb's precision and functional abilities.
What position is one in when they are lying on a bed and gazing up at the ceiling?
In the medical context, the term "supine" refers to the body's position when lying face-up with the back and the posterior surface of the body in contact with the supporting surface, such as a bed or a floor. In the supine position, the person's face is directed upward, and the abdomen faces upward.