Week 1: Levers of musculoskeletal system

axis of rotation

In the centre of whichever joint we are looking at

First class lever

Axis is in middle of effort (force of muscles) and resistance

Second class lever

Resistance is in middle of effort (force of muscle) and axis.

Like a wheelbarrow

Third class lever

Effort (force of muscle) is in between the axis and the resistance

Which lever am I?

Calf muscle

Second class lever

Which lever am I?

Neck muscles

First class lever

Which lever am I?

Elbow flexors

Third class lever

What is an effort arm?

The force of the muscle

What is the resistance arm?

The force of the resistance

Anatomy directions: Superior refers to...

Towards the head

Anatomy directions: Inferior refers to...

Away from the head, towards the feet.

Anatomy directions: When saying right and left we are referring to....

The individual's right and left sides, not from our perspective.

Anatomy directions: Distal refers to...

Away from the body's core or attatchment of the extremities.

Anatomy directions: Proximal refers to...

Towards the body's core

Anatomy directions: Anterior refers to...

The belly side/front side

Anatomy directions: Posterior refers to...

The back side

Anatomy directions: Medial refers to...

The midline of the body

Anatomy directions: Lateral refers to...

Away from the midline of the body

The sagittal plane is...

What movements occur in this plane?

A vertical plane which divides the body into left and right halves.

Forward and backward movements, as well as flexion and extension occur in this plane.

The frontal plane is...

What movements occur in this plane?

A vertical plane that passes through the body, dividing it into anterior or posterior halves.

Lateral or side movements, such as abduction and adduction or elevation and depression of the scapula occur in this plane.

The transverse plane is...

What movements occur in this plane?

A horizontal plane which divides the body into top and bottom halves.

Rotation movements, such as rotation, pronation, and supination occur in this plane.

Movement term: Abduction is...

Movement of a joint away from the midline of the body.

Movement term: Adduction is...

Movement of a joint towards the midline of the body

Movement terms: Flexion is...

The decrease of an angle between two joints.

Movement terms: Extension is...

An increase of an angle between two joints

Movement terms: Medial/internal rotation and lateral/external rotation is...

Movements around an imaginary line running through the long bone of a joint.

Movement terms: Circumduction is...

A circular motion that occurs at a few joints, including the neck, shoulders and hips.

Active motion is....

When the patient moves the joint

Passive motion is...

When the motion is done to the patient.

Resisted motion is...

When resistance is placed on the motion

Joint type: Synovial joint is...

The most common joint in the body. It has an articular capsule with an outer fibrous layer and a inner synovial layer that secretes synovial fluid.

Examples of synovial joints are ball and socket joints, hinge joints, pivot joints, condylar joint, saddle joint, and plane joint.

Joint type: Fibrous joint is...

Bones which are bound by tough fibrous connective tissue, with little to no mobility.

Examples of fibrous joints include sutures (which are found between the bones of the skull), gomphoses (found in the mouth where the roots of the teeth articulate with the dental alveoli), and syndesmoses (formed by ligaments and a strong membrane that holds 2 bones in place)

Joint type: Cartilaginous joint is...

Bones that are connected by fibrocartilage or hyaline cartilage.

Sub classification: Synchondroses and symphyses.

Synchondroses are primary cartilaginous joints where the bones are connected by hyaline cartilage, and will eventually become completely ossified in adulthood. Symphyses are secondary cartilaginous joints where the bones are connected by fibrocartilage, and are found primarily along the midline of the body.

Mobility of joint: Diarthrosis is...

A freely mobile joint, such as the knee joint.

Mobility of joint: Amphiarthrosis is...

slightly mobile joints, such as the pubic symphysis.

Mobility of joint: Synarthrosis is...

An immobile joint, such as the coronal suture of the skull.

What are the 5 components of a lever system?

1. Axis of rotation

2. Effort arm

3. Resistance arm

4. Effort force vector

5. Resistance force vector

Mechanical advantage =

Effort arm divided by resistance arm

True or false:

Balancing the resistance and effort torque creates an equilibrium

True

What factors influence strength?

- Larger muscles

- Shorter levers/moment arm

- Our ability to generate torques

Starting with the pelvis, list the bones of the lower limb from proximal to distal.

1. Pelvis

2. Femur

3. Tibia

4. Fibula

5. Talus (Metatarsal)

6. Calcaneus (Metatarsal)

7. Phalanges (proximal, middle and distal)

What type of joint is the shoulder?

Synovial joint, ball and socket.

What type of joint holds the pelvis together?

Fibrous joint

What type of joint is the knee?

Synovial Joint, Hinge Joint

Of the 3 major joint types, which 2 are the only ones which we need to name movements?

Synovial and cartilaginous joints

What movements of the scapulae occur when we abduct our shoulders through 180 degrees?

External rotation, abduction, elevation.

What are the major scapulae movements during the concentric phase of a seated cable row?

Internal rotation, adduction