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Upon completion of this chapter, the learner should be able to demonstrate the following competencies and proficiencies concerning tissue healing:

  • Describe the four types of tissue.

  • Describe common injuries.

  • Describe the signs and symptoms of acute inflammation.

  • Describe the pathology of acute inflammation.

  • Describe the pathology of chronic inflammation.

  • Identify the normal, acute, and chronic physiological responses to trauma.

  • Describe the physiological processes of trauma, wound healing, and tissue repair and their implications on the goals in rehabilitation


To develop successful therapeutic exercise protocols, clinicians need a strong understanding of tissue healing. Clinicians should be able to recognize phases of healing, understand treatment goals, and appreciate precautions required to avoid impairing the healing process, thus delaying the patient's return to activity. Each injury initiates a unique healing response with variable clinical presentations, regenerative capabilities, and rate of healing. Healing is influenced by the severity of injury, involved tissues, location of injury, patient characteristics (e.g., age, concurrent pathologies), and numerous other factors. Understanding how to recognize and treat common characteristics of each phase may facilitate the healing response and return to activity.

The healing response can be divided into three phases: inflammatory response, repair/regeneration phase, and remodeling phase. During the inflammatory response, chemical messengers elicit local and systematic effects, cells remove debris, and cells create the groundwork for the repair and regeneration phase. In the repair/regeneration phase, cells restore the vascular and structural integrity of injured structures. Finally, the injured region undergoes a remodeling phase, which allows the healed tissue to adapt to functional loading. The three phases are not discrete events—they overlap. Disruption at any time of the healing response can result in an unsatisfactory outcome.

Clinical Pearl 2-1

Healing responses are commonly divided into three overlapping phases: Inflammatory: acute injury and clean up Repair/Regeneration: restoration of blood flow and structure Remodeling: structural adaptation to functional loading


When an injury occurs, trauma often alters several types of tissues. Tissues are composed of cells and extracellular matrix, which contains water, fibrous proteins, glycoproteins (protein with a small sugar molecule), polysaccharides (sugars), nutrients, and metabolic waste. There are four unique types of tissues (i.e., epithelial, connective, muscle, and nervous) defined by type and function of cells, composition of extracellular matrix, and the ratio of cells to extracellular matrix (Fig. 2-1). Epithelial tissue is composed of layers of closely spaced cells that cover organ surfaces and serve for protection, secretion, and absorption. Examples of epithelial tissue include epidermis (skin; protection), inner lining of the digestive tract (absorption), glands (secretion), and inner lining of blood vessels.

Figure 2-1.

The four types of tissue: connective, epithelial, muscle, and nervous tissue.

Clinical Pearl 2-2

The type and function of tissues ...

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