A Report On Structural Kinesiology: Analysis Of The Functions Of Different Muscles

Directions: Utilizing the knowledge gained in this course, review and answer each of the following questions.

1. Describe two movements of the same joint; differentiate agonist and antagonist muscles for each.

Elbow Joint; Ginglymus or hinge- type joint. One movement that it allows is flexion. The elbow flexes at the coronoid fossa. Flexion is the movement of the forearm to the shoulder by bending the elbow to decrease its angle. Flexion is from 0 to 150 degrees. The stability in flexion depends on the radial and ulnar collateral ligament. The elbow flexor muscles are the biceps brachii, brachialis, brachioradialis, and the pronator teres. The agonists are the biceps brachii, brachialis, and the brachioradialis. The antagonist muscles are the triceps brachii and the anconeus. The other movement that the elbow joint allows is extension. The elbow extends at the olecranon fossa. Extension is the movement of the forearm away from the shoulder by straightening the elbow to increase its angle. Extension is from 150 to 0 degrees. The elbow extensor muscles are the triceps brachii and the anconeus which are also the agonists for elbow extension. The antagonist muscles are the brachialis, biceps brachii, and the brachioradialis.

2. Identify 2 methods of strength gain and categorize them according to which body system is adapting. Analyze the mechanisms of cause each.

One method of strength gain would be to lift weights. This helps to tone, lift, firm, and shape your body. The muscular system would be the one to adapt. The heavier the weights that you lift then the stronger you will be. Your muscles will slowly increase in size as you keep lifting heavy weights because your body will try to adapt to that weight. When lifting you are activating a lot of fast twitch (Type II) muscle fibers. When you add mechanical stress, it puts damage to the muscle tissue which signals satellite cells to create new muscle protein. Another method of strength gain would be explosive training. The muscular system would be the one to adapt. Explosive training mixes strength and speed to give you a bigger power output. Athletes normally use this when in need of a quick burst of maximal effort.

3. Distinguish between stability and mobility of joints, describing the relationship between the two and what physical factors affect each.

Joint mobility is the range of motion in which two bones that meet have before being restricted by the deep connective tissue that is around it. The physical factors that affect this could be ligaments, tendons, muscles, etc. Having mobility is just in the name, you are able to be mobile using certain parts of your body so you should be able to move without any restraints on that joint. Mobility is the degree of locomotion around a specific joint or articulation. Joint stability is being able to keep or sway the movement of your joints and the position that they are in. The connective tissue that borders your joints and the neuromuscular system work together to stabilize these movements. The physical factors that affect this are the shape of the articular surfaces, ligaments, and muscle tone. The shape, size, and arrangement of the articular surfaces matter for stability. Tears in a ligament and sprains can negatively impact stability in the joint. All joints are mobile and stable to a certain degree. They are inversely related to each other.

4. Compare and contrast the structure and function of the upper and lower limbs.

The upper limbs consist of the arm, forearm, and hand. 30 separate bones form the bony framework of each upper limb. These limbs specialize in mobility. The skeleton of the arm is composed of the humerus. It is a long bone that articulates with the scapula at the shoulder and with the radius and ulna at the elbow. The skeleton of the forearm is composed of the radius and the ulna. Their proximal ends articulate with the humerus, and their distal ends form joints with bones of the wrist. The radius and ulna articulate with each other proximally and distally at the radioulnar joints, and they are connected along their entire length by the interosseous membrane. The radius lies laterally, and the ulna lies medially. The ulna is a little bit longer than the radius. Its main job is to form the elbow joint with the humerus. The radius is thin at its proximal end, and wide at its distal end. </p><p>The radius is the major forearm bone that contributes to the wrist joint. When the radius moves so does the hand. The skeleton of the hand consists of the carpals (wrist), metacarpals (palm), and the phalanges (bones of the fingers). The carpal is located at the proximal part of our hand. It consists of 8 marble sized short bones closely held together by ligaments. Gliding movements occur between these bones so as a whole they are very flexible. The metacarpals radiate from the wrist to form the palm of the hand. These small long bones are numbered 1-5 starting at the thumb. The bases of the metacarpals articulate with the carpals proximally and with each other medially and laterally. Their bulbous heads articulate with the proximal phalanges of the fingers. The phalanges are numbered 1-5 starting with the thumb. Each hand contains 14 of these miniature long bones. With the thumb as an exception, each finger has 3 phalanges which are the distal, middle, and proximal. The thumb doesn’t have the middle one.

The lower limb consists of the thigh, leg, and foot. These limbs specialize in weight bearing and locomotion. The skeleton of the thigh is composed of the femur. It is the largest, longest, and strongest bone in the body. The femur articulates with the hip bone proximally, and then courses medially as it descends toward the knee. The skeleton of the leg is composed of the tibia and fibula. This is the region of the lower limb between the knee and the ankle. These two bones are connected by an interosseous membrane and articulate with each other proximally and distally. The tibiofibular joints of the leg allow no movement, compared to the joints between the radius and the ulna of the forearm which allow movement. The bones of the leg form a less flexible but stronger and more stable limb than those of the forearm. The fibula lies laterally, and the tibia lies medially. The tibia articulates proximally with the femur to form the modified hinge joint of the knee, and distally with the talus bone of the foot at the ankle. It receives the weight of the body from the femur and transmits it to the foot. The fibula is a sticklike bone with slightly expanded ends. It articulates proximally and distally with the lateral aspects of the tibia. The fibula doesn’t contribute to the knee joint and helps stabilize the ankle joint. The skeleton of the foot consists of the tarsals, metatarsals, and phalanges. The foot supports our body weight, and it acts as a lever to propel the body forward when we walk and run. The tarsals are a total of seven bones that form the posterior half of the foot. It is similar to the carpals of the hand. Your body weight is carried by the talus (ankle) which articulates with the tibia and fibula superiorly, and the calcaneus (heel bone). The calcaneus forms the heel of the foot and carries the talus on its superior surface. The metatarsals are five small long bones. They are numbered 1-5 starting with your big toe. The arrangement of the metatarsals is more parallel than that of the metacarpals of the hands. The metatarsals articulate with the proximal phalanges of the toes distally. The 14 phalanges of the toes are smaller than the ones of the fingers. Their general structure and arrangement are the same.

5. Explain how the structure of the spinal column is suited to its function. Be sure to provide an in-depth explanation for each spinal segment.

The spinal column is a flexible, curved support structure. It consists of 7 cervical or neck vertebrae, 12 thoracic or chest vertebrae, 5 lumbar or lower back vertebrae, 5 sacrum or posterior pelvic girdle vertebrae, and 4 coccyx or tailbone vertebrae. The spine extends from the skull to the pelvis, where it transmits the weight of the trunk to the lower limbs. It also surrounds and protects the spinal cord and provides attachment points for the ribs and for the muscles of the back and neck. The first two cervical vertebrae shapes allow for extensive rotary movements of the head to the sides, forward, and backward movements. The thoracic spine curves anteriorly and the cervical and lumbar spine curve posteriorly. These curves allow it to absorb blows and shocks. Vertebrae increase in size from cervical to lumbar regions to support more weight in the lower back. The body of the cervical vertebrae is oval and except for C7 the spinous process is short, projects directly back, and is split at its tip. The vertebral foramen is large and triangular. The body of the thoracic vertebrae is heart shaped. It has two small facets, one on the superior edge and the other on the inferior edge. The demifacets receive the heads of the ribs. The vertebral foramen is circular, and the spinous process is long and points sharply down. The superior and inferior articular facets lie in the frontal plane which limits flexion and extension but allows this region to rotate. Lateral flexion is possible but is restricted by the ribs. The lumbar region receives the most stress. They have a sturdier structure to be able to maintain. Their bodies are huge, and kidney shaped in a superior view. The pedicles and laminae are shorter and thicker compared to the other vertebrae. The spinous processes are short, flat, and hatchet shaped. They are robust and project directly backward to adapt to the attachment of the large back muscles. The vertebral foramen is triangular. The orientation of the facets of the articular processes of the lumbar vertebrae are very different from the other regions. This is so the lumbar vertebrae are locked together and to provide stability by restricting rotation of the lumbar spine. Flexion and extension are possible and so is lateral flexion. The triangular sacrum shapes the posterior wall of the pelvis. It supports the weight of the upper body as it is spread across the pelvis and into the legs. The coccyx is our tailbone which is small and triangular. It gives slight support to the pelvic organs, but it is nearly useless.