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LASER Therapy


It is recent modality of Physiotherapy and stands for Light Amplification by Stimulated Emission of Radiation.
Production of Laser: It is produced by the excitation of the atoms of some elements through electromagnetic radiations.

Type of Laser:

1         Power Laser
2         Soft Laser
3         Mid Laser
Ø  Power Laser is used for the destruction of tissues or surgical purposes.
Ø  Soft Laser is used in skin diseases.
Ø  Mid Laser is used for the therapeutic purpose. It is used by the Physiotherapist as their dept of penetration is sufficient to produce biological effects in deeper tissues without damaging the skin.

Mid Laser:

In Physiotherapy two types of Mid Laser are used.

o   One type of Mid Laser contains Helium – neon Laser combined with infrared Laser having wavelengths of 630 nm and 904 nm respectively. Both combine are used to treat the deeper tissues i.e. 30mm from surface. It should be placed at 30 cm distance from the surface of patient to be treated.
o   In another type, there is only infrared Laser and will be placed in contact with the surface of patient. The depth of penetration will be 30 mm.

Physiological effects of Laser:

Physiological effects of Laser are same just like other radiation by the processes of reflection, refraction and penetration depending upon the wavelength, nature of the tissues and angle of incidence.
Angle of incidence for the Laser should be 90°. It may be attenuated partly due to the divergence from the angle of incidence, partly due to the absorption and partly due to reflection.
Laser on getting entry to the body leads to increase kinetic energy at molecular level and cellular level. The depth of penetration of Laser is due to photochemical effect. The following are the physiological effects of Laser.

o   Cellular effects:

It activated the electron transport chain, increases ATP synthesis and reduction of the cellular PH. Laser also initiate reactions at cell membrane through its photochemical effect on the Ca channels. These biochemical effects (electron transport chain, ATP synthesis, and decrease cellular PH) and cell membrane changes cause increase macrophages, fibroblasts and lymphocyte activities (wound and Fracture healing)

o   Effect on nerve conduction and nerve regeneration:

Some studies shows that it increases the nerve conduction, some shows that it decreases the nerve conduction and some shows that it has no effect on nerve conduction. It decreases the sensory latency.

o   Effects on vasodilatation:

It increases microcirculation which may help in wound healing by the phenomenon of vasodilatation at capillary level.

Indications/ Therapeutic effects of Laser Therapy:

Ø  Wound and fracture healing
Ø  Arthritic conditions at distal extremities
Ø  Musculoskeletal disorders
Ø  Pain Management

Contraindications:

v  Patient with active or suspected carcinoma
v  Recent radiotherapy (4 – 6 months)
v  Areas of hemorrhage
v  Direct irradiation over a pregnant uterus
v  Local to the endocrine glands

Precautions for the use of Laser:

ü  Epilepsy
ü  Fever
ü  Eye (glasses to be wear)
ü  Confused or disoriented patient
ü  Infected tissues
ü  Sympathetic ganglion
ü  Vagus nerve
Cardiac region in cardiac patients

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Infrared radiations


Infrared rays are electromagnetic waves with wavelength of 750 – 4 lac nanometer. Any hot body emits infrared rays. For example the sun, gas fire, coal fire, electric fire, hot water pipes etc. The infrared rays are produced by two types of generators.
  1. Luminous generator
  2. Non luminous generator

Non luminous generator provides infrared rays only while luminous generator emits visible and a few ultraviolet rays as luminous generator is often called radiant heat. The term infrared is generally being applied to the radiations from non luminous source.

Therapeutic uses of infrared:

A.  Pain relief:

Infrared radiation is an effective mean of relieving pain, when heating is mild the relief of pain is due to sedative effect on superficial nerve endings. Stronger heating of infrared stimulate the superficial nerve endings. It has been also noticed that pain is due to accumulation of waste product and because of stronger heating the blood flow increases which remove that waste product and the pain is relieved. In some cases the relief of pain is probably associated with muscle relaxation.
                                               
In acute inflammation, pain is reduced with mild heating because in recent injury tissue fluid accumulates in that area, the use of stronger heating will increase these processes which cause pain.
In chronic type of inflammation pain is reduced due to stronger heating. The infrared causes comfortable warmth and the treatment time should be round about 30 min.

B.  Muscle relaxation:

Muscle relaxes most readily when the tissue is warm. The relief of pain also facilitates muscle relaxation. Infrared radiation is most helpful to achieve muscle relaxation and for the relief of muscle spasm associated with acute injury or inflammation.

C.  Increased blood flow/ supply:

The effect of infrared is mainly in the superficial tissues and this may be used in the treatment of superficial wounds and infections. Because a good supply of blood is essential for healing to take place and if there is infection, the increased number of WBCs and the increased exudation of fluid assist in the destroying of bacteria. When superficial joints are affected for example small joints of hand and feet (arthritis), the infrared radiation is more helpful in the vasodilatation of blood vessels. This vasodilatation can increase the blood flow (increased supply of oxygen and removal of waste product and food stuffs are available to bring about the resolution of inflammation).

Application of infrared treatment:

The intensity of radiation should be low at the beginning but after 5 – 10 min when the vasodilatation occur (when the increased blood flow establishes). The strength of radiation may increase; this can be achieved by moving the lamp nearer to the patient. The physiotherapist should be at the hand throughout the treatment session and should reduce the intensity of radiations when the heating become excessive. Sweating is encouraged if the patient is provided with water drink.

Dangers of infrared radiations:

     i.        Burn:

Infrared radiations can cause superficial heat burn. Red patches are seen on the skin which subsequently blisters during or after the treatment. The burn is most often caused by 2 grade intensity of radiation. This process can occur when the patient does not understand the nature of treatment or fails to report the overheating or move neat the lamp or falls asleep. The physiotherapist must be at hand during the whole treatment session.

   ii.        Electric shock:

It can occur as a result of touching some exposed part of the circuit but the main danger arises if the live wire comes in contact with the apparatus casing.

  iii.        Gangrene:

Gangrene may be occurred when infrared is applied to the area of defective arterial supply.

  iv.        Headache:

Headache may occur if the sweating does not take place properly or if the treatment is given in hot weather.

    v.        Faintness and Giddiness:

Extensive irradiation may cause fall in BP which may result in faintness or giddiness due to hypoxia of the brain.

  vi.        Injury to the eyes:

It has been suggested that exposure to IRR can cause cataract.

Contra – indications:

a)      Defective arterial supply
b)      Defective skin sensation
c)      Areas where there is danger of hemorrhage

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Paraffin wax therapy


Paraffin wax bath therapy is an application of molten paraffin wax over the body parts. The combination of paraffin and mineral oil has low specific heat which enhances the patient’s ability to tolerate heat from paraffin better than that from the water of the same temperature. The composition of solid wax: liquid paraffin, mineral oil and petroleum jelly. 

Paraffin wax bath

Methods of application of wax:

Patient preparation:

·         Check the sensitivity of patient
·         Dry the skin if wet
·         The treatment part should be in relax position

Preparation of paraffin wax:

·         Heat the paraffin wax up to therapeutic temperature (50 – 52°C).
·         Paraffin liquid and petroleum jelly should be added.

There are four methods of application of paraffin wax therapy and the treatment is given for about 10 – 20 minutes.
1.       Dipping method (Direct immersion)
2.       Wrapping method (bandaging)
3.       Brushing method
4.       Pouring method

1        Dipping method (Direct immersion):

In this method, the body part to be treated is directly immersed into the container of paraffin wax for 2 – 3 seconds and taken out. After 2 – 3 seconds the part is again immersed to make another layer of paraffin wax. This process is repeated 6 – 12 times until 3 – 4 mm layer is formed, and then wrapped around by plastic sheet and towel. This method is preferably used for treating distal parts of the body.

2        Wrapping method (bandaging):

A roll of bandage is immersed in molten paraffin wax and then wrapped around the body part. This method is preferably used for treating proximal parts of the body.

3        Brushing method:

A brush of various sizes is used for the application of molten wax over the body tissues. This method is used for proximal joints i.e. shoulder, elbow and knee joints etc.

4        Pouring method:

The molten wax is directly poured by a utensil on the part to be treated and then wrapped around by a towel.

Therapeutic effects:

Arthritic conditions:

In arthritis conditions like RA, particularly for the stiff and painful joint and the distal part of the body such as hands, feet, paraffin wax is helpful before mobilization exercises. The heat produce by the paraffin wax reduces the pain and soften the joint.

Painful conditions:

In painful condition affecting the joints due to trauma or disease paraffin wax is of value to decrease pain and enhancing function e.g. sprain, strain.

Stiff joints:

Paraffin wax therapy decreases pain, soften the joint and also increases the mobility.

Chronic inflammation:

In chronic inflammatory condition with oedema and stiffness affecting joints, paraffin wax is of value important to decrease oedema and increase softening of joint.

Contra indications:

·         Open wound
·         Skin infection
·         Defective skin sensation
·         Ischemic conditions
·         Skin allergy

Dangers:

·         Burns
·         Aggravation of inflammation

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Heat


Thermal effects:

The factors affecting thermal effects are the following.
·         Volume of tissue absorbing energy (heat)
·         Composition of tissues (proteinous are more sensitive to heat)
·         Capacity of tissue to dissipate heat
·         Rate of temperature rise

Effects of heat on body:

Cellular effects:

Metabolic activities are increase by the rise in temperature i.e. 13 % of metabolic activities is increased by 1°C rise in temperature. When the metabolic activities increase the demand for O2, nutrients also increases and more waste products are produced. Accelerated cellular metabolism can produce many beneficial therapeutic effects to treat injury or infection.
Effects on blood flow:
When the skin is heated the surface become reddens and the blood vessel dilated increasing the blood flow. For the healing if there is infection a good blood supply that beings more WBCs kill bacteria can assist n the process. Increase in metabolism leads to release to CO2 and lactic acid leading to greater acidity of the tissues which causes dilatation of the vessels. Histamine and tissue dilators substances such as bradykinin are also released by the greater heating of the tissues. They also help in the dilatation of vessel.

Effects on collagen tissues:

Some specific tissues in the body such as collagen tissues are sensitive to heat. It has been shown from previous study that above 50°C temperature (40 - 45°C) the extensibility of collagen tissues has been increased. This only occurs if the tissue is simultaneously stretched and requires temperature near the therapeutic limit.

Neurological effects of heat:

↓ muscle tone:

Heating of the tissues to therapeutic range (40 – 45°C) results in the reduction of the muscle spasm. Ia afferent of the muscle spindle have been shown to increase their firing rates with raise in temperature while most secondary to pathological changes afferent decreases firing rate with the rise in temperature.
Heating will stimulate the Golgi tendon organ. ↑firing of Golgi tendon organ resulting in increase inhibition. All these factors will reduce the muscle tone.

Relieve of pain:

Pain is relieved by the application of heat due to decreased nerve conduction velocity or elevated pain threshold. It may be due to sedative or counter irritation effect of heat. Pain relieve is associated with relieve of muscular spasm and increase in joint range of motion.

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Difference between Iontophoresis and Phonophoresis


         i.            Iontophoresis uses electric current to transport ions into tissues through skin while Phonophoresis uses acoustic energy (ultrasound) to drive molecules into the tissue through skin.
       ii.            Iontophoresis has immediate effect while Phonophoresis has prolong effect
      iii.            The treatment time for Iontophoresis is 15 – 20 min while that for Phonophoresis is 5 -10 min.
     iv.            Iontophoresis is done through electrode while Phonophoresis is through probe (transducer head)
       v.            In Iontophoresis there are chances of chemical burn while Phonophoresis is safe.
     vi.            Iontophoresis is painful while Phonophoresis is painless.
    vii.            Iontophoresis is difficult method while Phonophoresis is simple method

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Phonophoresis (sonophoresis) (ultrasonosonophoresis)



Phono means sound and phoresis means migration of the ions through a membrane by the action of an electric current.
Phonophoresis is defined as the movement of the drugs through skin into the subcutaneous tissues under the influence of ultrasound.

Phonophoresis depends upon:

·         Intensity of ultrasound
·         Frequency of ultrasound
·         Nature of drugs
In 1950s, they said that the drugs goes 4 – 5 cm deep to the skin while recent study shows that drugs go 1 -2 mm deep into the skin.
Phonophoresis

Indications:

·         Bursitis
·         Tendinitis
·         Medical interest of transcutaneous systemic delivery of substances such as insulin that cannot be delivered effectively by mouth
·         For superficial effects, cutaneous anaesthetic are delivered by frequency devices

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Therapeutic Ultrasound


Sound is the mechanical disturbance of an elastic medium such as air. Vibrations which travel through the air or another medium are called as sound. The frequency of hearing sound is 20Hz – 20,000Hz.
Ultrasound means the above the frequency of sound or the sound waves which are produced above the 20,000 Hz.
Therapeutic Ultrasound

Production of Ultrasound:

For a one mega Hz frequency machine vibrating source with a frequency of one million pulses/s (million cycles/s) is needed. This is achieved by using either quartz crystal or barium crystal. These crystals deformed when subjected to various potential differences (Piezoelectric effect). The basic components of Ultrasound apparatus are the following.
o   Source if high frequency current
o   Cable
o   Link electrodes
o   Barium or Quartz crystal
o   Metal plate

Working:

Source of high frequency current which is conveyed via co – axial cable to a transducer circuit or ultrasound head. Inside the ultrasound head the high frequency current is applied to a quartz or barium crystal through link electrode, the meal plate being fused with the quartz crystal. Any change in the shape of quartz crystal causes movement of the metal plate which in turn produces ultrasound waves. Strict control of high frequency current (1 MHz or 3 MHz) produces a steady or regular ultrasound waves.

Parameters of ultrasound:

Intensity (watt):

The unit of intensity when using ultrasound is watt. But this is a gross measure of power transmitted by the treatment head.  So, an average intensity will be used. There are two types of intensities.

Space average intensity:

The average intensity over a specified area is given (watt/cm²). This is used for continuous ultrasound.

Time average/space average intensity:

It can be given when ultrasound being applied in a pulsed mode and gives average intensity over the whole treatment time for a specified area e.g. if 0.5 watt/cm² is applied in a pulsed mode at 1 : 4 then in 1 second, the average intensity will be 0.1 watt/cm², if ultrasound is continuous.

Reflection of ultrasound:

Sound waves obey the laws of reflection and if an ultrasound beam travelling through one medium passes to another medium (encounter) which will not transmit this ultrasound beam, reflection will take place. For example, air will not transmit the ultrasound waves. So in ultrasound treatment care should be taken that air will not left between the treatment head and the body surface to minimize reflection.
However, there will be some reflection at interface that ultrasound beam encounter; this will give rise to acoustic impedance. If acoustic impedance is low transmission will be high and vice versa.

Transmission of ultrasound:

If the ultrasound beam encounter between two media and is transmitted it may be refracted deflection from original path when travelling from one medium in which its velocity is low to a medium having high velocity, it might be refracted from its normal path.
Significance of refraction is that if x is a target refraction would cause the ultrasound beam to miss it. Refraction will not occur when the incident wave travelling along the normal direction, treatment should be given with majority of wave travelling along the normal direction. Refraction will not occur if the ultrasound head is used perpendicular to the body surface.

Attenuation of ultrasound:

Reduction in the intensity of ultrasound beam once it has left the ultrasound head is called attenuation of ultrasound. Reduction may occur by the following two processes.
·         Absorption
·         Scatter
Ultrasound beam are absorbed and converted into heat and reduced its intensity is called absorption. This occur when normal ultrasound beam is deflected from its path by refraction i.e. air bubbles in the tissues. The overall affect of these two as such that the ultrasound beam is reduced in intensity, the deeper it passes, this give rise to the expression of half values distance  which the depth of the soft tissues that reduces the ultrasound beam to half its surface intensity. The half value distance for soft tissue is different for different frequencies i.e. for 1MHz is 4cm and for 3MHz is 2.5cm. In practice (treatment practice) when treating deep structures consideration needs to be given to the frequency and intensity of ultrasound.

Coupling media:

Ultrasound cannot be transmitted through air therefore medium is used for it. 100 %waves cannot be transmitted but only %age can be transmitted through skin having medium. The following are the media which transmit the ultrasound waves.

Aqua sonic gel
72.6 %
Glycerol
67 %
Distal water
59 %
Liquid paraffin
19 %
Petroleum
0 %
Air
0 %


Air will in fact reflect the ultrasound waves back into the treatment head and this could set up the standing waves which might damage the crystal.

Physiological effects of ultrasound:

Thermal effects
Non thermal effects

Thermal effects:

The heat absorbed by the tissue depends upon the following.
a.       Absorption of tissue:
Protein absorbs more heat. So, tissue having more protein will absorb heat.
b.       Insonated tissues:
Those tissues which are exposed to ultrasound produce much heat which have power of increase circulation.
c.       Number of treatment sessions
d.       Continuous produce ultrasound
e.      Periosteum will reflect the ultrasound waves leading to standing waves. It causes burning sensation in bony area. So avoid ultrasound on bony prominence.

Non thermal effects:

        i.            Mechanical effects (micro-massage):

This is where the longitudinal compression waves of the ultrasound produce compression/rarefaction of the cells and effects the movement of the tissue fluid in the interstitial space. This can help to reduce the oedema combined with the thermal effect, the extensibility of the scar and adhesions could be affected in such away to make stretching them easier.

      ii.            Biological effects:

It helps to reduce inflammation.
·         Inflammation: ultrasound increases the fragility of lysosome and thus enhances the release of their enzymes. These enzymes will help to clear of debris (waste product) and allow the next stage to occur.
·         Proliferative stage: Fibroblast and myofibroblast may have calcium ions driven into these injured area and the collagen fibers are formed. This is called proliferative stage.
·         Remodeling stage

Uses of ultrasound:

Recent injury and inflammation:

Mechanical effect causes the removal of exudates. Thermal effects accelerate protein synthesis which helps in the repair of the damage tissue.

Chronic scars:

The thermal effect of the ultrasound is also use for the removal of chronic scar by stretching the tissues.

Chronic oedema:

Mechanical effect and thermal effect of ultrasound help in the removal of oedema.

Dangers of ultrasound:

Burn:

If the continuous ultrasound is used with stationary head will cause burn in the tissue. When ultrasound is use o bony prominence, the waves cannot be absorb by the Periosteum and reflect them causing burn in the underlying tissues.

Damage to the equipment:

When the head of ultrasound treatment remains in air will produce standing waves which damage the treatment head crystal of ultrasound.

Contraindications of ultrasound:

·         Thrombophlebitis
·         Acute sepsis (the presence of pus-forming bacteria or their toxins in the blood or tissues)
·         Tumors
·         Radiotherapy (up to 6 month) has devitalizing effect on the tissue so ultrasound is contraindicated
·         Pregnancy
  • Cardiac diseases

Under:
Cryotherapy


Cryo – Ice, low temperature
Therapy – treatment
                The treatment of pathological lesion by the use of low temperature agents such as ice, frozen gel packs and vapocoolant sprays. It has clinical application in therapeutic s and diagnostics, so is widely used in rehabilitation and other areas of medicine. It exerts its therapeutic effects by influencing hemodynamic, neuromuscular and metabolic processes.

Physiological effects of Cold:

Hemodynamic effects:

When cold is applied to the body it causes an initial decrease in blood flow due to the vasoconstriction of the cutaneous blood vessels. This vasoconstriction persists if the duration of the cold application is limited to less than 15 – 20 minutes. The vasoconstriction caused by cold is brought about both by the direct and indirect mechanisms.

Direct effects:

Ø  Increases viscosity of blood ----- decrease blood flow -----vasoconstriction
Ø  Activation of the cutaneous cold receptors -----stimulates the smooth muscles of the blood vessel walls to contract-----vasoconstriction

Indirect effects:

Ø  Decrease production and release of vasodilator mediators such as histamine and prostaglandin-----reduced vasodilatation
Ø  Decreased sympathetic adrenergic activation----- decrease production and release of vasodilator mediators such as histamine and prostaglandin----- reduced vasodilatation

Lewis hunting effect:

The immediate vasoconstriction response to cold may be followed by marked vasodilatation which itself may last for some 15 minutes before being replaced by another episode of vasoconstriction.
Lewis in 1930 observed that after 15 minutes of cold application, causing vasoconstriction, there is cyclic vasodilatation followed by vasoconstriction. This effect is called Lewis Hunting effect.

Neuromuscular effects:

Cold has a wide effect on the neuromuscular function;

a)     Reduces the nerve conduction velocity:

The nerve conduction velocity decreases in proportion to the degree of cooling. Decreased nerve conduction velocity has been documented with five minutes of application of cold, it fully reverses after 15 minutes. Cold can decrease the velocity of conduction ion both sensory as well as motor nerves.  It has greater effect on myelinated and small diameter fibers than unmyelinated and large diameter fibers.

b)     Increases the pain threshold:

A decrease in pain after cold application is due to increased pain threshold, through pain gate mechanism and reduction of muscle spasm and sensory nerve conduction velocity (especially small diameter myelinated pain transmitting fibers)

c)      Facilitates muscular contraction:

Brief application of cold facilitates the muscle contraction by enhancing excitability of the alpha motor neuron.

d)     Decreases spasticity:

It reduces spasticity for 1 – 1.5 hours, if applied for 30 minutes.

Metabolic effects:

Cold reduces the metabolic rate contrary to the heat that is why it is used in acute inflammation
It reduces the production of cartilage destroying enzymes i.e. collagenase, elastase, protease, hyaluronidase, etc that is why this modality is highly recommended in Acute osteoarthritis, rheumatoid arthritis, etc.

Techniques for application of Cryotherapy:

The various techniques that are used for administering cold are:
1         Ice towel
2         Ice packs
3         Immersion
4         Excitatory cooling/Ice massage

1       Ice towel:

This is popular method of application because there is little danger of producing an ice burn.

Patient preparation:

·         Prepare the bed
·         Remove the bed sheath
·         Remove the clothes from the area to be treated
·         Put water proof sheath on the bed like plastic etc

Ice towel preparation:

·         Prepare the ice solution by filling the bucket with two parts of crushed ice to one part water
·         Towel is immersed in the bucket and then wrings to remove excess water

2       Ice packs:

An ice pack is consisting of a gel made from silica or a mixture of saline and gelatin, which is covered by a plastic covering. The ice pack is rolled in a towel and applies the area to be treated.

3       Immersion:

In this technique the part to be treated is immersed in an ice solution (50% ice and 50% water). The technique is used for distal parts such as the hand and feet. The part to be treated is either immersed for a single 10 minutes session or a series of shorter immersions are made until a cumulative total of 10 minutes has been reached.

4       Excitatory cold:

The sensory stimulus of ice on the skin can be used to facilitate contraction of inhibited muscle. The ice is stroked quickly three times over the dermatome and skin is ten dried. This sensory stimulus passes via the peripheral nerve and enters the cord through posterior horn. It raises the level of excitation around the anterior horn cell (as ACH has connection with these sensory fibers) ultimately leading to contraction of inhibited muscles.

Indications of Cryotherapy:

Cryotherapy is indicated in the following conditions:
        I.            Acute injury:Cryotherapy is widely used to control acute inflammation and to accelerate recovery from injury.
o   It decreases fluid filtration into interstitium by vasoconstriction
o   It decreases inflammation
o   It reduces metabolic rate
o   It reduces pain and muscle spasm
o   Ice therapy is also applied with compression and elevation of the limb.

    II.            Acute burn:

Cooling decrease magnitude of injury by:
o   Reducing oedema
o   Reducing fluid loss
o   Reducing pain
o   Reducing further tissue injury
o   Decreasing blood volume during the 1st 48 hrs

 III.            Acute spinal cord injury:

Patient with acute spinal cord injury also improved with hypothermia. It was noted that complete destruction of the spinal cord may not occur at the initial moment but relates to self destructive process in cord.

  IV.            Decreasing spasticity:

It decreases the nerve conduction velocity. It increases the muscular contraction so applied on antagonist (process of stroking).

     V.            Reduction of fever:

Cold sponging during fever reduces the temperature.

  VI.            Tendinitis

VII.            Bursitis

VIII.            Arthritis etc

Contraindications:

Ø  Open wound
Ø  Cardiac disease:
                                Arrhythmias, Myocardial Infarction etc
Ø  Hypersensitivity:
Raynaud’s disease (excessive vasospasm)
Cold urticaria
Cryoglobinemia
Ø  Peripheral vascular diseases:
Arteriosclerosis (affect artery)
Atherosclerosis (affect vein)

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