Posterior Tibialis Tendonitis

RapidForce I Shape - Muscle Support & Pain Relief System

RapidForce® Shapes stabilize and support the muscles, tendons, and ligaments in the 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.

Posterior tibialis tendonitis is most common in hikers, rock climbers, and athletes who make sudden or repeated foot movements.

The posterior tibial tendon is located in the lower leg, behind the shin muscle, and is the anatomical part that allows athletes to walk, run, flex, and bend the knee, making it one of the most important in the body. But its necessity to and constant use in even basic movements also makes it acutely susceptible to overuse and subsequent inflammation, tears, or tissue damage.

Symptoms of tendonitis in the foot or ankle include muscle weakness, joint tightness, limited range of motion, instep pain, pain inside the foot that spreads into the leg, and even changes in foot shape. The pain area can be tender to the touch and can appear red, warm, or swollen. Posterior or anterior tibial tendonitis often has a gradual onset, getting progressively more painful over the course of a few days or weeks.

The RapidForce® I Shape is designed to help reduce pain in the foot or ankle, especially pain deriving from posterior tibialis tendonitis. 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 tibial tendon and lifting the upper layers of the skin. The resulting mechanical lift is intended to better circulate and deliver blood, oxygen, fluids, 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 Posterior Tibialis Tendonitis Pain

I Shape

From $6.95

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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 arm a minimum of 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. Prop the foot or ankle

    1. Prop the foot or ankle

    Place the ankle at a 90 degree angle (from foot to lower leg) for the most effective application.

  2. 1. Prop the foot or ankle

    2. Anchor the end of I Shape

    Peel off one end of the shape’s backing. Orient the shape so it is approximately 45 degrees to the foot. Place the end tab over the outer heel. Press to secure the bond.

  3. 1. Prop the foot or ankle

    3. Apply remainder of I Shape - 1" Stretch

    Peel the backing from the largest area of the I Shape, leaving the opposite end tab in place. While stabilizing the end tab on the heel with one hand, stretch the shape’s arm, wrapping it beneath the foot and securing it on the outer portion of the lower leg. Smooth the fabric onto the skin, moving from the end tab upwards.

  4. 1. Prop the foot or ankle

    4. Secure and Bond

    Remove the backing from the end tab and secure to the skin. Do not stretch this small end piece. Press down on the entire I Shape for about 10 seconds to secure bond.

  5. 1. Prop the foot or ankle

    5. 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.