Physics in physical therapy

Physical therapy focuses on motion and also the recoincredibly of that activity.physics is applicable to torque and also forces as the body bends, stretches and also moves. physics deserve to be used to a number of subjects in kinesiology, physiology, and biomechanics.

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Think of the body’s skeletal mechanism as a mechanism of pulleys and levers. the exercise that are supplied in therapy deserve to be characterized by newton’s laws of movement, examples-

the initially law: performing aerobic exercise on rubber mats rather of hardwood floors.the second law: resistance band exercise.the 3rd law: stamina training

Because of the science behind physics, the physical therapy area is able to flourish and also advance in technique of learning about the body and also just how to treat it.

The mechanical values utilized in exercise therapy are identified here to ensure


Force is that which produces the motion or modifies the movement of an item and also moves it for a certain distance. it is a vector top quality i.e. magnitude and also direction.

Force=mass(kg) × acceleration(m/s²)

Unit of force: newton and also pound. < one-newton is defined as the pressure applied in the 1kg weight object and moves it for 1 meters distance.>Force might act on object in 2 way:-

Static- when object in remainder.Dynamic- as soon as object is in motion

Types of force acting on object:-

A) Linear force- when 2 pressures act alengthy same line and create the directly line motion is referred as straight pressure.

Pushing straight force→as soon as 2 force are acting on a things in same direction produces direct motion.pulling direct force→ once the two pressures pull an item in same direction it produces the straight activity.equal magnitude (equillibrium)→once the two pressure are acting opposite to each other via the equal magnitude.unequal magnitude→when the 2 forces are acting oppowebsite to each various other with unequal magnitude, the movement occurs in the direction of the higher magnitude.

B) Parallel force- once two equal magnitude are acting in the very same direction and same aircraft through the counter pressure in the middle.

example; sea -saw , the kids are using the 2 pressures in the end, and the fulcrum gives counter force to preserve the see-experienced in neutral place.

example in huguy body- when the deltoid muscle contracts during shoulder abduction, the activity of the anterior and also posterior fibers of the muscles being compound to work-related with the middle fibers and so vastly raising their power.

C) Rotational force- in parallel force once first force is higher then second pressure, rotation occurs. two unequal pressures acting at different points and in opposite directions develop rotation of the body.

instance in huguy body- when the trapezius muscle and also serratus anterior muscle contract to rotate the scapula.

With respect to body pressures are two types

1)External force- pressure aclimb from sources outside the body.example-

Gravityoutside device included to body, prefer wet-cuff, spring,by physio pulley-block and so on.

2)Internal force- force that act on structure of body that aries from the body’s very own framework. example muscle, ligament, bone. this pressure arisen within the body.


Gravity is the force whereby a world or various other body draws objects towards its facility. pressure by which all the bodies are attracted to earth is gravity.

What else does gravity do?

Why perform you land also on the ground as soon as you jump up instead of floating off right into space? Why carry out things loss dvery own once you throw them or drop them? The answer is gravity: an invisible pressure that pulls objects toward each various other. Earth’s gravity is what keeps you on the ground and what renders things loss.



BOS implies the area supported beneath the object.if base of assistance is even more the stcapability will certainly be more.BOS∝1/COG and STABILITY∝ BOSIn the lying position the posterior aspect of the totality body creates the stride standing it is a space as wide as the feet.the fundamental position of standing the BOS is lesser than the lying, so COG in the standing position it is in the higher level whereas in the lying posture.


A state when the forces acting upon a body are perfectly well balanced and the body remajor at remainder. it is the state of an item where all the pressure acting on it are equal in magnitude and also oppowebsite in direction.


steady equilibrium:- wbelow two forces acting on a things are equal. example- book put on the table. the BOS is even more and also COG lies in the reduced part.unsteady equilibrium:- as soon as 2 forces acting on an object are pressure is better than various other.example-pen is well balanced to stand also on the floor,as soon as force applied on pen it changes its original state. BOS is less and COG is in higher place.

See more: Mechanical Engineering Minor In Mechanical Engineering < University Of Miami

neutral equilibrium:-as soon as the motion or place adjust in the object by the force exerted on it, tbelow will not be any type of change in COG of object. example- round rolling on floor.


Lever before is a rigid bar/ part which is qualified of activity around a addressed point referred to as as fulcrum (F). in lever work is done once a force of effort (E) applied at one allude on the lever before acts upon an additional pressure or weight (w) acting at a second allude on the lever before.

To perdevelop an activity or a activity the bones act as the lever before and also the joint act as the fulcrum (F).The activity will certainly be developed by two forms of pressures i.e. weight (w) and effort (E).in which the weight(W) is the opposing pressure and the effort(E) is activity achieving force.W is the weight of the body parts and also initiative might be the pull of the muscles.

Types of lever:- There are three classes of lever-

A) First order lever-

In this kind of lever fulcrum is between the initiative and also weight.fulcrum may be shifted centrally or in the direction of weight or initiative.example- see-experienced, scissors, nail-cutter.essential attribute of initially order lever is stcapability.example in humale body ATLANTO-OCCIPITAL JOINT. in the time of the nodding activity of the head; neck extensors act as the→effort(E); the facial component is the→weight(W); atlanto-occipital joint as the→fulcrum(F).

B) 2nd order lever-

In these weight is in in between the fulcrum and also effort.example-Wheelbarrowhead.These are the lever of toughness however not the rate and also ROM.example in huguy body- standing on toes; in which the bevery one of the toes→fulcurm(F); the tendo-achilles tendon is →effort(E); the body weight is passing through the middle component of the foot→weight(W).

C) Third order lever-

In this initiative is in between fulcrum and weight.example- Bettle nut cutter, chapati push.these lever having actually greatly mechanical disadvantage.however the 3rd order levers are viewed plenty in the huguy body.example in human body- elbow flexion; in which the elbow→fulcrum (F); the biceps insertion→effort(E); the forearm and also hand→weight.


A pulley is a grooved wheel which is rotated about a resolved axis by a rope which passes round it.

A pulley-block is a straightforward device or machine made of a wheel with a rim that a cord or rope fits around. The wheel and also axle of a pulley-block make it less complicated to lift heavy objects with the rope.

These are different kinds of sheave systems:

Fixed: A fixed pulley-block has an axle placed in bearings attached to a supporting framework. A addressed pulley changes the direction of the pressure on a rope or belt that moves alengthy its circumference. Mechanical advantage is acquired by combining a resolved wheel via a movable sheave or an additional addressed sheave of a various diameter.Movable: A movable sheave has actually an axle in a movable block. A single movable wheel is supported by 2 parts of the same rope and has a mechanical advantage of 2. this form of sheave is provided in the suspension therapy units which provides easy to lift the body parts.Compound: A combicountry of resolved and a movable pulleys creates a block and also tackle. A block and also tackle have the right to have actually several pulleys installed on the solved and relocating axles, better raising the mechanical benefit.

Pulley in huguy body example-



Anatomical plane is a hypothetical plane provided to transect the human body, in order to explain the place of frameworks or the direction of motion.

Three major planes are used:

THE SAGITTAL PLANE OR MEDIAN PLANE( longitudinal, anteroposterior) is a plane parallel to the sagittal suture. it separated the body into left and best.THE CORONAL PLANE OR FRONTAL PLANE is perpendicular to the ground, in humans it separates the anterior from the posterior, the front from the back, the ventral from the dorsal.THE TRANSVERSE PLANE OR AXIAL(HORIZONTAL) PLANE is parallel to the ground, in humale it separates the exceptional from the inferior, the cranial from the caudal.


An axis is a directly line about which an object rotates. Movement at the joint take area in a airplane about an axis. Tright here are three axis of rotation.

Sagital axis – passes horizontally from posterior to anterior and is formed by the intersection of the sagital and also transverse planes.Frontal axis – passes horizontally from left to right and is developed by the interarea of the frontal and also transverse planes.Vertical axis – passes vertically from inferior to exceptional and is created by the interarea of the sagital and also frontal planes.