Notes#16: 4 Types of Joints

• Blank piece of paper

We Move in Different Ways

Types of Joints• Immovable (ex. Skull)

• Movable 4 types of movable:1. Hinge: Back & forth, ex.

Knee2. Ball & Socket: Greatest

movement, ex. Hip, shoulder

3. Pivot: Rotation, ex. Neck4. Gliding: Side-to-side &

limited movement, ex. Wrist

Double-Jointed?

• Hypermobile joints are not doubled/extra in any sense• Approximately 5% of the healthy population have one or more

hypermobile joints. • Is a weakly stabilized joint because of loose ligaments or

tendons• Their joints may be easily injured, be more prone to complete • Can lead to chronic pain or even disability in severe cases.

– Musical instrumentalists with hypermobile fingers may have difficulties when fingers lock

– Also may display superior abilities due to their increased range of motion for fingers.

Knuckle Cracking

• Knuckle "cracking" has not been shown to be harmful or beneficial. More specifically, knuckle cracking does not cause arthritis (inflammation of joints).

• Joint "cracking" can result from a negative pressure pulling nitrogen gas temporarily into the joint

• "Cracking" sounds can also be heard if tendons snap over tissues because of minor adjustments in their gliding paths.

• If cracking is accompanied by pain, there could be underlying abnormalities of the structures of the joint, such as loose cartilage or injured ligaments.

Broken Bone? Splint vs. Cast• Splints are removable, breathable, and flexible• Casts are rigid and have to be cut off