Bones, Joints, and Movement

Written Learning Objectives 

PDF Download

1. Understand the basics of bone markings/macroscopic bone anatomy terminology.

The macroscopic appearance of bone varies based on the function of that area of bone (e.g. muscle tendon/ligament attachment, neurovasculature entering/exiting bone, joint formation, etc.) and between individuals. Understanding the basic terminology of macroscopic bone anatomy will assist in further osteological analysis.

A basic division of osteological landmarks includes: depressions/openings & projections/processes.

Depressions and openings have two main functions: allowing the passage of soft tissue through or along bone and formation of joints. The articular surfaces of bone (joint formation) are smooth, as they were covered with articular cartilage during life.

See Table 1 for a list of depressions/openings that are commonly found on bones of upper/lower limbs.

Table 1: Osteological landmarks: depressions/openings (note: you do NOT have to memorize the definitions - these are here to help you understand and reference when learning pertinent named osteological structures)

Projections and processes have two main functions: formation of joints and attachment points for connective tissues (muscle tendons, ligaments). See Table 2 for a list of projections/processes that are commonly found on bones of upper/lower limbs.

Table 2: Osteological landmarks: projections/processes (note: you do NOT have to memorize the definitions - these are here to help you understand and reference when learning pertinent named osteological structures)

2. Identify bones and major bony landmarks of upper and lower limbs.

(Videos by Anatomy faculty showing and describing the bones and bony landmarks of upper & lower limbs. These specifics will help familiarize yourself with the osteology, and will be particularly helpful for the practical. These specifics will not be on the quiz/final exam unless also covered in another Learning Objective or Active Learning Session)

Upper Limb Osteology

Lower Limb Osteology

3. Describe the classification of joints. Discuss the basic characteristics of the three types of joints.

Joints classification schemes are often very specific to discipline, but two major means of classification are common: joint structure & range of motion allowed. You are responsible for knowing classification based on joint structure.

With this scheme, joints are classified according to the type of tissue that unites the articulating bones and how the tissue attaches the bones. There are 3 main types:

In fibrous joints, bones are joined by fibrous connective tissue, and the degree of movement depends on the length of fibers uniting the bones.

In cartilaginous joints, the surfaces of the articulating bones are covered with hyaline cartilage (articular cartilage), and bones are united by strong fibrous tissue and cartilage. These joints tend to be strong and slightly moveable.

Synovial joints are unique in that bones are connected via an articular capsule rather than a continuous sheet of connective tissue. This organization allows for free movement between bones.

All synovial joints have:

4. Describe accessory structures of synovial joints.

While all synovial joints have an articular capsule, articular cavity, and articular cartilage, many of the more complex synovial joints will have accessory structures that play a role in the protection, support, etc. of the joint.

The most common structures are ligaments. Ligaments connect bone to bone and can be either intrinsic (thickening of capsule) or extrinsic (separate from capsule). This differs from tendons, which connect muscle to bone. Both ligaments and tendons (and commonly muscle bellies) play important roles in structural integrity of joints.

Labra, articular discs, and menisci are all composed of predominantly fibrocartilage and have slightly different compositions and functions. Labra are typically associated with ball and socket joints and form a lip around the socket portion to provide a better fit for the ball portion of the joint. Articular discs can be complete or incomplete and can serve to divide an articular cavity into 2 components (as in the temporomandibular [TMJ] joint) or as a shock absorber. Menisci are similar in function to labra, but are typically incomplete.

Bursae are sac-like structures (very similar in composition to a synovial capsule with synovial fluid) that are often associated with synovial joints, particularly in areas of increased friction. Specialized bursae surrounding long tendons are often referred to as tendon sheaths.

5. Understand the types of movements that may occur at synovial joints.

6. List and describe the six types of synovial joints, and include examples of each type.

7. Identify the major joints and associated ligaments in the shoulder region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Videos

Acromioclavicular joint

The acromioclavicular (AC) joint is located at the articulation of the acromial end of the clavicle and acromion of the scapula. It is an example of a plane joint (gliding/sliding of scapula on clavicle).

Glenohumeral (shoulder) joint

The glenohumeral (shoulder) joint is the most mobile [ball and socket] joint in the body, and with this high level of mobility, there is decreased stability. Accessory structures play a dominant role in structural stability. The glenohumeral joint is formed by the head of the humerus and glenoid cavity of the scapula. The glenoid cavity is very shallow and accepts only ~1/3rd of the humeral head.

8. Identify the major joints and associated ligaments in the elbow & forearm region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Videos

There are 3 articulations associated with a shared articular capsule in the elbow region.

Accessory structures of elbow region:

Remaining joints of forearm:

9. Identify the major joint and associated ligaments in the wrist region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Videos

The radiocarpal (wrist) joint involves the articulation of the distal end of radius and proximal row of carpals (excluding the pisiform), and is a synovial, condyloid joint. In regards to surface anatomy, this joint is located approximately at the level of the proximal wrist crease. It is important to note that the ulna does not form a direct articulation at the wrist joint. The actions of the radiocarpal joint are very closely aligned with those created at the distal radio-ulnar and intercarpal joints.

Accessory structures of radiocarpal (wrist joint):

There are multiple joints in the hand including:

10. Identify the major joint and associated ligaments in the hip region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Videos

The hip joint is a synovial, ball and socket joint, and is the second most mobile joint in the body (2nd to the glenohumeral joint - both ball & socket joints). The joint is formed by the acetabulum of the coxal bone and head of the femur. Medial and lateral rotator muscles of the thigh play an important role in support and structure of the hip joint.

Accessory structures of hip joint:

11. Identify the major joint and associated ligaments in the knee region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Video

The knee joint is a modified hinge joint which is capable of a small degree of medial and lateral rotation, particularly from a flexed position. The knee joint is actually a complex of 3 articulations: patellofemoral and lateral & medial tibiofemoral joints. When observing the articular surfaces of the medial and lateral condyles of the femur and tibia, one can observe the notable incongruence of the articulation structures. Due to this incongruence, accessory structures are vital to the structural integrity of this joint. 

Accessory structures of knee joint:

12. Identify the major joint and associated ligaments in the ankle & foot region. Explain what kind of movements occur at the joints and other pertinent information.

Movement Videos

The talocrural (ankle) joint is a hinge joint (dorsiflexion & plantarflexion) formed by distal fibula and tibia and the superior talus.

The [anatomical] subtalar joint is located at the articulation of the talus and calcaneus. A [clinical] subtalar joint is often described due to the functional similarities between the anatomical subtalar joint and talocalcaneonavicular joint, talocalcaneal part. These separate joints function in unison and are often considered together.

The transverse tarsal joint is a combined (compound) joint composed of the calcaneocuboid joint and the talocalcaneonavicular joint, talonavicular part. This joint assists and augments the eversion/inversion action.