Movement Analysis

Core aspects of human movement

1. Mobility

   • ability to move freely and efficiently

2. Function

   • How movement supports performance in tasks and roles

3. Occupation

   • Movements involved in meaningful daily activities and roles

4. Leisure

   • Physical activity related to enjoyment and recreation

reasons for movement dysfunction include

• disease, injury, or lesion affecting MSK or neuromuscular system

• post-immobilization

• disuse

• aging

• coordination and control issues

• psychosocial influences (fear avoidance)

internal factors which influence movement

• MSK system - muscles and joints

• Cardiovascular/respiratory system - energy systems - provide essential FUEL to work movement

• Nervous system - peripheral and central nervous systems

external factors which influence movement

• physical environment - external effects due to environment, forces

• social environment - context of movement in the society

facilitating factors for normal joint mobility

• bony shape

• articular cartilage

• capsule and synovial membrane

• elastic ligaments

• neuromuscular function

limiting factors for normal joint mobility

• articular surface contact

• limits of ligament extensibility

• limits of tendon and muscle extensibility

Physiotherapists analyse movement to look at …

• core of function

• diagnostic link

• treatment planning and evaluation

normal movement =

efficient, smooth, and adaptable movement of the joints/body

• neuromuscular control - efficient functioning of the nervous system - PNS and CNS

• muscle strength and tone - adequate force and tension in muscles

• joint mobility and stability - right balance of flexibility and support

• balance and coordination - maintain posture and balance during activities

• sensory feedback - appropriate functioning of the sensory systems such as vision, touch, and proprioception to adjust movement in real time.

pathological movement =

movement associated with …

• pain

• stiffness

• weakness

• incoordination

why is a a clear understanding of normal movement in healthy individuals important?

it is the foundation for RECOGNISING ABNORMAL movement. Understanding normal movement patterns allows for the identification of deviations. There should be a focus on common functional tasks such as squatting, reaching, and walking.

what does movement analysis encompass?

1. static and dynamic observation

2. functional movement / tests

3. specific movement evaluation (e.g. active rom)

4. biomechanical analysis

5. outcome measurement

Why should i analyse movement?

1. Diagnosis

   • gives a broad guide to how the condition can be managed

2. functional ability

   • guides goal setting and task focus

3. impairments

   • guide targeted assessment and treatment

   • measuring impairment level can help track progress over time.

   • if PROM good and AROM poor = contractile muscle problem

   • if AROM AND PROM poor = non-contractile/joint problem

Osteokinematics

Physiological motion

e.g. flexion and extension

Arthrokinematics

movement between articular surfaces (translation and rotation)

Muscle strength =

• ability to produce tension and a resultant force based on the demands placed on the muscle

• greatest measurable force that can be exerted by a muscle or muscle group to overcome resistance during a single, maximal effort.

Muscle power

• work produced by a muscle per unit of time = (force x distance) / time

• rate of performing work

Muscle endurance

Ability of a muscle to contract repeatedly against a load, generate and sustain tension, and resist fatigue over an extended period of time.

Concentric contraction

muscle shortens, and the force of the muscle overcomes the load

Eccentric contraction

muscle lengthens, and the force of the load overcomes the muscles force

Agonist / prime mover

muscles that contract to directly produce the desired joint movement

Antagonist

opposes or produces the opposite joint movement to the antagonist

Synergist

a muscle that stabilises a joint during movement, minimising the unwanted actions of agonists or enhancing their function, thereby allowing the agonist to perform effectively at the required joint

Fixator

Muscle that stabilises the origin of the agonist and the joint that the origin spans in order to help the agonist function most effectively at the joint required.

biomechanical/physiological influences of muscle performance

1. internal and external moment arm

2. muscle torque

3. resolution of muscle forces

4. muscle length-tension relationship

5. force-velocity relationship

6. active and passive muscle insufficiency

Moment arm

perpendicular distance from the line of force to the axis of rotation

Muscles moment arm (length)

critical in determining the moment generated by the muscle contraction

the larger the internal moment arm, the larger the muscle torque

Torque

Angular/rotatory force of the muscle which causes movement.

Resolution of muscle forces

the process of breaking down a single muscle force vector into two components based on its direction relative to a joint:

1. Rotational (Tangential) Component (MFₜ):

   • Acts perpendicular to the bone.

   • Responsible for producing joint rotation or torque.

   • This is the part of the force that contributes to movement.

2. Stabilizing or Distracting (Normal) Component (MFₙ):

   • Acts parallel to the bone.

   • Responsible for compressing (pushing into the joint) or distracting (pulling apart) the joint.

   • This component does not create movement, but affects joint stability.

Length-tension relationship

A muscles capacity to produce force depends on the length at which the muscle is held.

Maximum / optimal force is evident NEAR the muscles normal resting length / mid range

Force-velocity relationship

Active force continuously adjust to the speed at which the contractile system works

1. Isometric contraction generates more force than concentric contraction

   • no change in length = no change in velocity.

2. Slow shortening / concentric contraction generates more force than rapid shortening / concentric contraction

   (muscle may not have sufficient time to develop peak tension)

   • fast shortening = cross bridges detach quickly = no tension = no force

   • slow shortening = cross bridges in tact longer = higher tension = higher force

3. Eccentric contractions produce more force than either isometric or concentric contractions.

• In eccentric contraction, the muscle is actively lengthening under load.

• Cross-bridges are being pulled apart, but many stay attached longer because they resist being stretched.

• This adds resistance and tension, producing more force.

Active insufficiency

Force insufficiency

• attempting to contract over multiple joints leads to inadequate force generation, resulting in decreased function.

Passive insufficiency

Length insufficiency

• attempting to extend over multiple joints, leading to inadequate length, resulting in decreased range of motion