Achilles Tendonitis

RapidForce I Shape - Muscle Support & Pain Relief System

RapidForce® Shapes stabilize and support the muscles, tendons, and ligaments in the heel, ankle, or leg. The I Shape is designed to reduce swelling by gently lifting the skin above the pain point, which can help circulate blood, oxygen, fluids, and nutrients to an injury site.

The Achilles tendon is the largest tendon in the human body and is critical to both basic, day-to-day movements as well as complex movements needed for fitness and athletics. Most often the result of running, jumping, or balancing on tiptoes, pain in the Achilles tendon is frequently seen in runners, basketball players, football players, obstacle course racers and Spartan racers, and dancers.

Achilles tendonitis is often described as a sudden “pop” in the ankle, heel, or lower leg that results in muscle stiffness, enlargement or swelling of the tendon, bone spurs, constant and worsening pain, pain in the tendon itself, or severe pain along the vertical portion of the lower heel. Athletes describe the sensation of a damaged Achilles tendon as stiff, warm, burning, mild friction, or an ache in the back of the leg or heel immediately after activity.

The two types of Achilles tendonitis—Noninsertional and Insertional—are distinguished by which part of the lower ankle or foot is feeling the most pain. For athletes and active people, Noninsertional Achilles tendonitis is more common. NAT occurs when the tiny fibers in and around the tendon begin breaking down, tearing, and/or swelling. Pain from this condition is usually located in the middle part of the tendon, heel, or ankle. Insertional Achilles tendonitis, which is more common in non-athletes, usually results in pain in the lower portion of the heel, at the point where the tendon and the bone attach.

The RapidForce® I Shape is designed to reduce Achilles tendon pain and can be used for a variety of foot and ankle pains. The I Shape’s central core adheres to the skin above the area with the most pain, and its dual arms are stretched outwards, helping to support and stabilize the Achilles tendon and lifting the upper layers of the skin. The resulting mechanical lift is intended to reduce inflammation and swelling and encourage the circulation of blood, oxygen, fluid, and healing nutrients to the injury site.

RapidForce® Shapes are unlike any other pain-relief product on the market today. Each Shape’s patented design was carefully developed and perfected by a team of physical therapists, athletic trainers, engineers, and an ultrasound technician who sought to create a product that supports the muscles and helps relieve pain caused by muscle, tendon, joint, and ligament injuries. RapidForce® Shapes are used by athletes at all levels, including professional athletes, semi-pro athletes, and people who lead or want to lead an active lifestyle.

If you'd like assistance choosing the best RapidForce® Shape for your needs, please email us at

Disclaimer: Please see your medical professional with any kind of pain. Pain could be an indication of a serious condition. RapidForce® Shapes are not meant to replace professional medical advice, professional treatment, or a professional treatment plan.

RapidForce Shapes for Achilles Tendonitis Pain

I Shape

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Application Instructions

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Time it Right

While RapidForce® Shapes can be applied at any time, they should be applied 1–2 hours before beginning strenuous physical activity. The Shapes can start working is as little as two hours, but some applications take up to four hours.

Prep Skin Thoroughly

Wash and dry the skin to remove oils, moisture, and dirt. Trim or shave body hair; this helps create a more secure bond and more comfortable removal. Apply the provided Skin Tac liquid adhesive wipe. Allow 30 seconds for it to dry.

Customize Stretch

Secure the Shape’s central core to the most painful spot. For optimal performance, stretch the arms minimum 1". Application instructions vary based on Shape, so read and follow the instructions mailed with your shape(s).

Secure Bond

With both the Shape and the skin at room temperature, carefully begin applying the shape. Once the shape is secure, rub it vigorously to maximize adhesive bond to skin.

  1. 1. Anchor the end of the I Shape

    1. Anchor the end of the I Shape

    Peel off the backing of one end of the I Shape and secure to the bottom of heel. Press to secure the bond.

  2. 1. Anchor the end of the I Shape

    2. Apply remainder of I Shape - 1" Stretch

    Peel off the backing of the larger portion of the I Shape, leaving the opposite end tab in place. Point the foot slightly downward and stabilize the end tab on the heel with one hand. Customize the stretch for level of activity and pull upward toward the calf. (1" is ideal; do not pull taut.) Smooth the fabric onto the skin, moving from the end tab upwards.

  3. 3. Secure end tab

    Remove the backing from the last end tab and place on the skin; do not stretch this small piece. Press over the entire I Shape for about 10 seconds to secure bond.

  4. 1. Anchor the end of the I Shape

    4. Feel Relief and Remove

    You may begin feeling relief within a few hours. However, it could take up to 24 hours. RapidForce shapes can provide pain relief and muscle support for up to five days but can be removed at any time. To remove, pull from the end of the arms to the center. If hair is present, pull in the direction of the hair’s growth to reduce discomfort. For easier removal, use mild warm water in the shower and then remove the shape slowly.