
Hard (Bony) End Feel
Motion is stopped when bone contacts bone. Normal end for some joints. Abnormal if there are loose fragments in joint that stop the motion.

Soft End Feel
Motion is stopped by soft tissues being compressed. Normal for some joints. Abnormal if there is a boggy feel to motion, indication of edima.

Firm End Feel
Motion is stopped by soft tissues that have reached there limit of strech. If motion is limited this is a sign of tissue shortening.

Empty End Feel
Motion is stopped in response to pain due to guarding or patient request to stop. Always abnormal.

MMT 0
 Absent
 No palpable conraction

MMT 1
 Trace
 Muscle contraction present but no joint movement

MMT 2
 Poor 
 Cannot complete full ROM with gravity eliminated

MMT 2
 Poor
 Can move body segment with gravity eliminated

MMT 2+
 Poor +
 Can complete full ROM with gravity eliminated against some resistance (i.e. friction)

MMT 3
 Fair 
 Can complete more than half of ROM against gravity

MMT 3
 Fair
 Can move body segment against gravity with no other resistance

MMT 3+
 Fair +
 Can complete full ROM against gravity with minimal resistance

MMT 4
 Good 
 Can complete full ROM against gravity with less than moderate resistance

MMT 4
 Good
 Can complete full ROM against gravity with moderate resistance

MMT 4+
 Good +
 Can complete full ROM against gravity with less than maximal resistance

MMT 5
 Normal
 Can complete full ROM against gravity with maximal resistance

Force
An interaction, a push or pull, between two objects that can arrest, induce, or modify movement

Newton's First Law
 Law of Inertia
 Linear: Bodies remain at rest or in uniform motion until acted upon by an unbalanced force (momentum = mass x linear velocity)
 Angular: Bodies remaing at rest of in uniform angular motion until acted upon by unbalanced torques (momentum = mass x angular velocity)

Newton's Second Law
 Law of Acceleration
 Linear: The acceleration of a body is proportional to the net force applied to the body (force = mass x linear acceleration)
 Angular: The acceleration of a body is proportional to the net force applied to the body (torque = mass moment of intertia x angular acceleration)

Newton's Third Law
 Momentum
 For every action, there is an equal and opposite reaction
 Angular: with regard to torque

Friction
Friction = frictions coefficient x normal force
Normal force is the force perpendicular to the friction force

Inertial Force
 In human systems, movements in one segment can exert forces on adjacent segments
 Usually a proximal segment on a distal segment
 Inertia is the body's tendency to resist acceleration

Momentum
 Quantity of motion
 Linear: Momentum = mass x linear velocity (kgm/sec)
 Angular: Momentum = mass moment of inertia x angular velocity

Impulse
 amount of energy required to alter velocity or momentum
 Linear: Impulse = force x time (newtonsec)
 Angular: Impulse = torque x time

Work
 Work = force applied (N) x distance moved (m)
 Units are Joules
 W = F * s = m*a*s
 s = linear displacement
 F = m * a
 Negative work: when the direction of movement is opposite the direction of the force applied

Energy
 The capacity to do work
 Units in Joules
 Kinetic: KE = 1/2 mass x velocity^2: KE = 1/2mv^2
 Potential: PE = mass x acceleration due to gravity x heigh: PE = mgh
 TE = KE + PE

Power
 Work done per unit of time
 P = W/t
 Joules/sec = watts
 Function of applied force x velocity: P = Fv

ImpulseMomentum relationship
 Linear: F*t = m*∆linear velocity
 Because:
 momentum = m*v
 F = m*a = (m*∆v)/t
 Angular: T*t = mass moment of inertia *∆angular velocity
if the time and mass are constant, and the force increases, the velocity must also increase

Mechanical Advantage
 MA = df/dr
 MA = distance to force/distance to resistance

Effort (Internal) Moment Arm
Perpendicular distance between the fulcrum and the line of force of the effort

Resistance (External) Moment Arm
Perpendicular distance between the fulcrum and the line of force of the resistance

First Class Lever
 Fulcrum between the force and the resistance
 like a seesaw
 MA = df/dr
 MA </=/> 1
 ex: occiput on C1; open chain triceps contraction

Second Class Levers
 Resistance between fulcrum and effort force
 like a wheelbarrow
 MA = df/dr
 MA >1
 ex: calf muscles lifting heel

Third Class Levers
 Efferot force between fulcrum and resistance
 like a catapolt
 MA = df/dr
 MA < 1
 ex: most joints in the human body
 allows for increased excursion

Torque
 Torque = force * perpendicular distance to the line of action
 Torque = force * moment arm
 Torque = moment of inertia * angular acceleration
torque for M = My*IMA

Lever Arm
 Distance from the axis of rotation to the point of the applied force
 length of a particular segment
 fixed value

Moment Arm
 Perpendicular distance from the lineofaction to the axis of rotation
 changes relative to the position of the arm
 increasing moment arm increases torque

Mass Moment of Intertia
 Mass Moment of Inertia = an objects resistance to change in angular velocity
 Angular equivalent of inertia (mass)
 sum of all moments of inertia of all the mass particles the object contains

Angular Momentum
Angular momentum = moment of intertia x angular velocity

Angular Work
 Angular work = torque applied x angular distance moved
 Concentric contraction = positive work
 Eccentric contraction = negative work
 Isometric contraction = no work

Rotational Kinetic Energy
RKE = 1/2 x mass moment of intertia x angular velocity^2 = 1/2Iw^2

Angular Power
 Rate of doing work: work done per unit of time
 P = dW/dt
 P = Tw
 area under force curve gives power

Inertia
 An objects ability to resist change in velocity (acceleration)
 Linear: mass
 Angular: mass moment of inertia

Force/Torque Acceleration Relationship
 the amount of force to alter velocity (induce acceleration/deceleration)
 Linear: Forcer = mass x acceleration
 Angular: Torque = mass moment of intertia x angular acceleration

