Manual Therapy encompasses a broad group of sophisticated techniques performed by hand and by uniquely trained physical therapists. These may include mobilization or manipulation of soft tissues and skeletal joints.
What is soft tissue? Soft tissue includes fascia, muscle, tendons and ligaments located just under the skin. Fascia is a white membrane that wraps and connects the muscles, bones, nerves and blood vessels of the body. Think of it like the white fuzz inside an orange peel, connecting the "skin" and the "meat" of the orange.
Tendons are made of connective tissue and attach the muscle to the bone allowing joints to move. When restricted from scar tissue, joints move less freely causing pain with movement. Ligaments connect bone to bone providing support and stability to your joints. When scar tissue limits this mobility, manual therapy can assist in your return to function.
Instrument Assisted Soft Tissue Mobilization (IASTM) stems from the theory of Friction Massage that was first introduced in the United States in the early 1900s and based on the principles of James Cyriax. The technique is said to have evolved from Gua sha, which is a method used in Chinese medicine. 
IASTM is a skilled treatment that is performed by certified therapist and includes the use of specialized tools to manipulate the skin, tissue, muscle, and tendon by various direct compressive stroke techniques. IASTM can be made from varying materials, but the most common is stainless steel.
The Theory Behind IASTM:
When someone experiences inflammation, has a traumatic incident like a muscle tear or undergoes surgery, scar tissue forms around the affected area. A certain amount of scar tissue is needed during the early stages of the healing process, however in some cases an abundance of scar tissue is formed. If left untreated, it begins to limit the surrounding tissues and joints from moving freely. The buildup of scar tissue is referred to as adhesions. Adhesions can form anywhere in the body where soft tissue is responding to an injury such as surgery, trauma, inflammation or tearing. As adhesions grow, they connect multiple layers of healthy soft tissue to each other, further causing pain and limited range of motion. This is sometimes called fascial restriction.
During IASTM treatments, direct compressive strokes are applied to break up these adhesions and initiate the remodeling of injured soft tissue. As tissue loosens, the body gains mobility and experiences decreased pain, allowing for proper strengthening.
Our day to day activities can also cause wear and tear on our bodies, even though it may not be as prevalent as a surgery or traumatic incident. Our lifestyles may naturally cause tissues to adhere to each other irregularly or cause muscle imbalances. These muscle imbalance are commonly caused by poor posture.
IASTM has been shown to provide a wide range of benefits including increased range of motion, flexibility, reduced pain and improved circulation. With the IASTM technique, it can assist in muscle fiber separation, which releases pain and increases functional mobility. IASTM must be applied with exercise and stretching programs to enhance the tissue remodeling.
IASTM can be used for many of these conditions affecting the body, both acute and chronic:
Cupping is an ancient medical treatment popular in Egyptian, Chinese and Middle Eastern countries that gained popularity in the US after Olympic Gold Medalist Michael Phelps was seen with “red spots” caused by the treatment on his back during the 2016 Olympics. Many athletes have since popularized cupping in the U.S. in recent years.
The Theory Behind Cupping:
The cupping process uses negative pressure by pulling an area of skin into a suction separating the tissue layers. The “marks" are reflective of the health of the tissue layers beneath the skin. Darker marks represent the longer standing tension (tightness) and stagnant blood flow within that area. Toxins and fluid are drawn under the skin so that the lymphatic system can drain it through the body. The cupping process breaks down adhesions and increases mobility. New and healthy blood then flows through the area.
Functional cupping can also be performed and applies a combination of the cupping treatment with the performance of movement or exercise. This brings healthy blood flow to the area for healing while increasing the flexibility or strength of the muscle.
TRIGGER POINT RELEASE
Trigger points can be described as “knots” in your muscle causing muscle tension that decreases blood flow to the effected area and eventually builds up toxins in the muscle. If untreated, these trigger points can grow over time and cause pain in different areas of the body. For example, a “knot” in a neck muscle can cause headaches or a “knot” in a hip muscle can cause pain in the groin. These trigger points can be released by applying pressure techniques while stretching the specific muscle. Your therapist will educate you on the steps to take after releasing trigger points to maintain flexibility and blood flow while reducing the chances of toxins building back up.
 Cheatham SW, Baker R. Kreiswirth E. Instrument assisted soft-tissue mobilization: A commentary on clinical practice guidelines for rehabilitation professionals. International journal of sports physical therapy. 2019 Jul; 14 (4):670.