Tarsals (7 ankle bones) A. talus – bone just below the tibia and fibula. 1. the only tarsal bone that articulates with the tibia and fibula. 2. It initially bears the weight of the entire body when walking.

More ankle bones B. Calcaneus – heel bone 1. largest and strongest of the tarsals 2. half the weight is transferred to it from the talus when walking.

Calcaneus Talus

More ankle bones C. Cuboid – between the calcaneus and the metatarsals. D. Navicular – between the talus and cuneiforms E. Cuneiforms (3) between the navicular and the metatarsals.

Navicular Cuboid Cuneiform

3 2 1 Cuneiform

Chew…. Name all the foot bones you know so far for your partner using the foot bone models.

Figure 6.27 Right Foot

Foot bones Metatarsals (similar to the metacarpals of the palm) Numbered 1 to 5 from the medial to the lateral. Each has a base, a body and a head.

5 4 3 2 1 Metatarsals

More foot bones Phalanges (similar to fingers of the hand) A. Hallux – big toe 1. Has only 2 bones B. Other toes have 3 phalanges – proximal, middle and distal

Proximal Middle Distal Phalanges

Hallux

Figure 6.27 Right Foot

Chew…. Name all the foot bones for your partner using the foot bone models.

Arches of the foot: Functions of the arches: Support the weight of the body Distribute body weight over the parts of the foot Provide leverage when walking Absorb shocks by giving when weight is applied and springing back afterwards

Types of arches Longitudinal arches – extends front to back of the foot (medial and lateral) Transverse arch – formed by the navicular, cuneiforms and bases of the metatarsals Flatfoot – abnormally low height of the medial longitudinal arch.

Figure 6.28 Arches of the Right Foot

Male vs. Female skeletons Bone differences Male bones are larger and heavier than female bones Male points of muscle attachment (tuberosities, lines and ridges) are larger.

Male vs. female skeleton Structural differences Female pelvis is wider and shallower than the male pelvis. Pelvic inlet of the female is larger and more oval while the male is smaller and heart-shaped.

Male vs. Female skeleton Acetabulum of the female is small and faces anteriorly, the male’s is large and faces laterally. Obturator foramen in female is oval and the male is round.

Male vs. Female skeleton Pubic arch in the female is greater than a 90 degree angle and male is less. Differences exist due to pregnancy and childbirth to accommodate the growing baby and aid delivery through the pelvic bones.

Bunion – a deformity of the big toe caused by wearing shoes that are too tight.

bunion

Arthrology – The study of joints. Articulation = A joint (A point of contact between bones, cartilage and bone or teeth and bone.)  Kinesiology = The study of movement of the human body. Rheumatology = The field of medicine involved with joint diseases and related conditions.

I. Types of joints A. The structure of a joint determines its function based on how strong its connection is and how flexible it is.

1.The closer the bones are together, the stronger the joint is. But this also limits movement.

2. The flexibility is determined by the shape of the articulating bones, how tight the ligaments are that hold the bones together and the tension of the muscles and tendons.

3 types of joints: Synovial, fibrous and cartilaginous 1. Synovial joints – bones have a space between them called the synovial cavity which is surrounded by the articular capsule.

They are the most movable joints and allow several types of movement. Most joints are of this type. Ex. Knee, fingers, hips, shoulder, skull on the atlas and axis, wrist and ankles, etc. They allow several types of movement.

1. The synovial joint parts: a. Fibrous capsule of dense irregular connective tissue that attaches to the periosteum of the bone. b. Ligaments extend from the fibrous capsule to connect the bones of the joint to each other.

Figure 7.03 Structure of a Typical Synovial Joint ©2004 John Wiley & Sons, Inc. All rights reserved.

c. Synovial membrane lines the inside of the articular capsule. d c. Synovial membrane lines the inside of the articular capsule. d. Synovial fluid fills the inside of the articular capsule. (similar to uncooked egg white in consistency).

It becomes more gel-like with inactivity and thins as movement increases which is why a warm-up is important before exercise.

The articular capsule is made of the fibrous capsule and the synovial membrane together.

Figure 7.03 Structure of a Typical Synovial Joint ©2004 John Wiley & Sons, Inc. All rights reserved.

Chew… Draw and label a synovial joint using your white board.

Figure 7.03 Structure of a Typical Synovial Joint ©2004 John Wiley & Sons, Inc. All rights reserved.

3. Articular discs or menisci – pads of fibrocartilage that lie between the articular surfaces of the bones and are attached to the capsule. They allow bones of different shapes to fit together more tightly.

4. “Torn cartilage” = tearing of the articular discs in the knee 4. “Torn cartilage” = tearing of the articular discs in the knee. Common among athletes. 5. Bursae – Sacs found some synovial joints such as knees and shoulders to reduce friction.

a. Bursitis – inflammation of the bursa a. Bursitis – inflammation of the bursa due to trama, infection or excessive use. 6. Hyaline cartilage covers the ends of the bones of a synovial joint to reduce friction.

Chew… Discuss bursa, meniscus and their roles in joints. Explain bursitis and torn cartilage.

C. Fibrous joints – bones are held together by fibrous connective tissue rich in collagen and there is no synovial cavity between the bones. Little or no movement.

Example of fibrous joints: 1. Sutures between the skull bones 2. The distal articulation between the fibula and tibia. 3. The roots of the teeth in the alveoli of the maxilla and mandible.

Figure 7.01 Fibrous Joints ©2004 John Wiley & Sons, Inc. All rights reserved.

D. Cartilaginous joints – Bones are held together by cartilage and lack a synovial cavity. Little or no movement.

Examples of cartilaginous joints: Epiphyseal plate between the diaphysis and epiphysis of a bone. When it becomes an epiphyseal line is has ossified into bone instead of cartilage. 2. Pubic symphysis between the coxal bones of the pelvis.

Chew…. On your white board: List 3 types of joints. List major features of each. List examples of each.

Common joint disorders Rotator cuff injury – tears the supraspinous muscle tendon between the head of the humerus and the acromion of the scapula. Common in baseball pitchers and volleyball players.

More common disorders Separated shoulder – injury of the joint between the acromion and the end of the clavicle. Often caused by the shoulder striking the ground in a fall.

More common disorders Dislocation of the radial head – pulled away from the humerus. Common in children from swinging them around by the arms.

More common disorders ACL injury – injury of the anterior cruciate ligament which connects the tibia and femur posteriorly and laterally. It is stretched or torn in 70% of serious knee injuries.

Figure 7.11a-b Structure of the Right Knee Joint ©2004 John Wiley & Sons, Inc. All rights reserved.

Chew…. Describe: Rotator cuff injury Separated shoulder Dislocated radius ACL injury

More common disorders Sprain – stretches or tears ligaments but does not dislocate the bones. Strain – partially torn muscle.

More common disorders Rheumatoid arthritis – an autoimmune disease in which the body attacks its own cartilage and joint linings. Osteoarthritis – deterioration of the articular cartilage of joints caused by wear and tear.

Pictures used by permission from: Introduction to the Human Body, 6th edition by Tortora and Grabowski. Published by Wiley Publishing. Human Anatomy & Physiology, 8th edition by Marieb & Hoehn. Published by Pearson Publishing.