I am always surprised by the number of patients I see, who use heat on an acute injury. I feel that there is a great deal of confusion surrounding when to use heat and when to use ice on an injury, so I felt it important to address the issue.
It is important to understand a little bit about how the body heals to understand how and when heat should be used to treat injuries. There are three recognized phases to the healing process.
The first phase is known as the inflammatory phase. The goal during this phase is to protect the injured area from further injury while the body debrieds and contains the damaged tissue. When an injury initially occurs, there is damage to the soft tissue structures (ligament, muscle, and tendon) but also damage to the blood vessels immediately in the area.
The damage to the blood vessels causes fluids to build up in the injured area causing the swelling that is typically seen in a new injury. To help reduce the flow of fluid into the area and thereby reduce swelling, cryotherapy (cold applications) is the best modality to use right after an injury. Cold modalities can help slow down and decrease the circulation to the area thereby reducing swelling.
Heat applied during this phase is contraindicated because heat increases blood flow into the injured area significantly increasing the amount of swelling. Increased swelling prolongs the rehabilitation process because it takes time to reverse the process and remove the extracellular fluid.
This first phase of the healing process can last for several days depending on the amount of tissue damage. For most injuries, two days is the most common time frame for phase one and is when ice should ONLY be applied to injuries.
The second phase of the healing process is known as the proliferation phase and is characterized by the laying down of new tissue and the formation of scar tissue. Again, depending on the amount of damage to the injured area, this phase can begin on post-injury day three and last for several weeks.
IT IS DURING THIS SECOND PHASE OF HEALING THAT HEAT CAN BE APPLIED TO THE INJURIED AREA TO FACILITATE THE HEALING PROCESS. The athlete can determine if he/she has entered phase two of healing when the initial swelling and pain of the injury starts to decrease.
Heat therapies can also be used during the third and final phase of the healing process known as the remodeling phase. During this phase the new tissue laid down during phase two matures. This phase can last up to one full year depending on the type of tissue that was injured.
What are the physiological effects of using heat?
When heat is applied during the second phase of healing, a number of physiological effects occur including:
• Increase in circulation to help remove debris and waste products
• Increase in cellular metabolism
• Increase in capillary permeability
• Provide an analgesic effect
• Reduce muscle spasms
• Increase in oxygen and nutrients into the area to promote healing
• Increase in extensibility of muscle and connective tissue to help facilitate stretch and elongate tissue
Many of these effects apply to modalities that create heat deep within soft tissue (ultrasound). Superficial heat therapies only heat tissue within several centimeters of the body and can be beneficial for superficial injuries. However, joint and muscle injuries (depending on their location) may not receive the same benefits if they are located deeper within the body.
To heat deep tissue (up to 1 ½ inches deep), the modality most commonly utilized in the therapeutic setting is ultrasound. Although ultrasound has different settings and can be used for different purposes, continuous ultrasound can effectively heat deep tissue.
Ultrasound works on the principle of sound waves. The sound waves enter the tissue and are transferred into heat energy under the surface. Ultrasound is a very effective modality for increasing the tissue temperature of localized injuries to facilitate the heating process (see above list).
Injuries that are commonly treated with ultrasound include rotator cuff strains, quadriceps strains, hamstring strains, and all types of sprains. The deep heat created by the ultrasound facilitates healing in tissues that cannot be reached by superficial heat modalities.
What types of injuries can be treated by heat?
One of the most common injuries treated by heat is muscle spasms in the back area associated with muscular back strains. Because the back muscles have the unique ability to “splint” themselves to protect the injured area, initial treatment needs to focus on reducing the muscle spasms.
Heat has been found to be effective at reducing the pain associated with muscle spasms by providing an analgesic effect and relaxation effect for tight muscles. For small muscle spasms, moist or dry heat packs can be effective. Larger areas can be treated by full-body immersion in a hot whirlpool.
Heat therapy is also effective in increasing the range of motion of joints after injury. Once the swelling from the original injury begins to subside, the injured area can be heated using a warm whirlpool or hot pack for 10 -15 minutes.
Because tissue becomes more extensible after it has been warmed up, range of motion exercises can be performed after heating to improve joint motions. The goal is to gradually increase the range of motion of the joint and restore it to pre-injury levels. However, care must be taken to not push a joint through pain as this can actually reinjure the tissue.
Joint injuries that can benefit from superficial heating to increase joint movement after injury include sprained ankles, turf toe, knee sprains, elbow and wrist sprains, and thumb and finger sprains.
Superficial muscle strains can also benefit from superficial heating techniques based on the same principle as above. When muscle tissue is heated, it becomes more extensible and better able to stretch. Heat modalities should be used prior to stretching for 10 – 15 minutes. After heating, a gradual and progressive pain-free stretch can be applied to the area.
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It is important to understand a little bit about how the body heals to understand how and when heat should be used to treat injuries. There are three recognized phases to the healing process.
The first phase is known as the inflammatory phase. The goal during this phase is to protect the injured area from further injury while the body debrieds and contains the damaged tissue. When an injury initially occurs, there is damage to the soft tissue structures (ligament, muscle, and tendon) but also damage to the blood vessels immediately in the area.
The damage to the blood vessels causes fluids to build up in the injured area causing the swelling that is typically seen in a new injury. To help reduce the flow of fluid into the area and thereby reduce swelling, cryotherapy (cold applications) is the best modality to use right after an injury. Cold modalities can help slow down and decrease the circulation to the area thereby reducing swelling.
Heat applied during this phase is contraindicated because heat increases blood flow into the injured area significantly increasing the amount of swelling. Increased swelling prolongs the rehabilitation process because it takes time to reverse the process and remove the extracellular fluid.
This first phase of the healing process can last for several days depending on the amount of tissue damage. For most injuries, two days is the most common time frame for phase one and is when ice should ONLY be applied to injuries.
The second phase of the healing process is known as the proliferation phase and is characterized by the laying down of new tissue and the formation of scar tissue. Again, depending on the amount of damage to the injured area, this phase can begin on post-injury day three and last for several weeks.
IT IS DURING THIS SECOND PHASE OF HEALING THAT HEAT CAN BE APPLIED TO THE INJURIED AREA TO FACILITATE THE HEALING PROCESS. The athlete can determine if he/she has entered phase two of healing when the initial swelling and pain of the injury starts to decrease.
Heat therapies can also be used during the third and final phase of the healing process known as the remodeling phase. During this phase the new tissue laid down during phase two matures. This phase can last up to one full year depending on the type of tissue that was injured.
What are the physiological effects of using heat?
When heat is applied during the second phase of healing, a number of physiological effects occur including:
• Increase in circulation to help remove debris and waste products
• Increase in cellular metabolism
• Increase in capillary permeability
• Provide an analgesic effect
• Reduce muscle spasms
• Increase in oxygen and nutrients into the area to promote healing
• Increase in extensibility of muscle and connective tissue to help facilitate stretch and elongate tissue
Many of these effects apply to modalities that create heat deep within soft tissue (ultrasound). Superficial heat therapies only heat tissue within several centimeters of the body and can be beneficial for superficial injuries. However, joint and muscle injuries (depending on their location) may not receive the same benefits if they are located deeper within the body.
To heat deep tissue (up to 1 ½ inches deep), the modality most commonly utilized in the therapeutic setting is ultrasound. Although ultrasound has different settings and can be used for different purposes, continuous ultrasound can effectively heat deep tissue.
Ultrasound works on the principle of sound waves. The sound waves enter the tissue and are transferred into heat energy under the surface. Ultrasound is a very effective modality for increasing the tissue temperature of localized injuries to facilitate the heating process (see above list).
Injuries that are commonly treated with ultrasound include rotator cuff strains, quadriceps strains, hamstring strains, and all types of sprains. The deep heat created by the ultrasound facilitates healing in tissues that cannot be reached by superficial heat modalities.
What types of injuries can be treated by heat?
One of the most common injuries treated by heat is muscle spasms in the back area associated with muscular back strains. Because the back muscles have the unique ability to “splint” themselves to protect the injured area, initial treatment needs to focus on reducing the muscle spasms.
Heat has been found to be effective at reducing the pain associated with muscle spasms by providing an analgesic effect and relaxation effect for tight muscles. For small muscle spasms, moist or dry heat packs can be effective. Larger areas can be treated by full-body immersion in a hot whirlpool.
Heat therapy is also effective in increasing the range of motion of joints after injury. Once the swelling from the original injury begins to subside, the injured area can be heated using a warm whirlpool or hot pack for 10 -15 minutes.
Because tissue becomes more extensible after it has been warmed up, range of motion exercises can be performed after heating to improve joint motions. The goal is to gradually increase the range of motion of the joint and restore it to pre-injury levels. However, care must be taken to not push a joint through pain as this can actually reinjure the tissue.
Joint injuries that can benefit from superficial heating to increase joint movement after injury include sprained ankles, turf toe, knee sprains, elbow and wrist sprains, and thumb and finger sprains.
Superficial muscle strains can also benefit from superficial heating techniques based on the same principle as above. When muscle tissue is heated, it becomes more extensible and better able to stretch. Heat modalities should be used prior to stretching for 10 – 15 minutes. After heating, a gradual and progressive pain-free stretch can be applied to the area.
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