The piriformis is functionally important as a lateral rotator at the hip joint and for its role in stabilizing the sacroiliac joint. It is also functionally important for its relationship to the sciatic nerve (Image 1; see The Piriformis and Piriformis Syndrome, page 69). Because the piriformis has multiple roles, it is valuable for therapists to have expertise and comfort working with it. One major manual therapy treatment approach when working on the piriformis is stretching. This article explores the many ways the piriformis can be stretched, comparing and contrasting the relative benefits of each method.

What is Stretching?

Stretching is essentially a simple mechanical process. It is a manual/movement therapy aimed at making a soft tissue longer. This occurs via a fundamental characteristic of soft tissue known as creep, which states a soft tissue will deform (change shape) in response to a sustained force placed upon it. In the case of stretching, the deformation/change is for the tissue to become longer.
When musculature is stretched, in addition to the mechanical effect of lengthening, we also have a neurologic effect in which the baseline tone of the musculature is decreased, relaxing the musculature and allowing it to be even more effectively lengthened. Lengthening and relaxing myofascial tissue allows greater range of motion at the joints crossed and, therefore, more ease with movement of the body.

How is Stretching Accomplished?

Knowing how to stretch a muscle, or any soft tissue, is extremely simple and can be figured out instead of memorized. Approaching how to figure out the stretch of a muscle can be done in two ways. One method is to visualize moving the attachments of the muscle away from each other. The second method is to move the client’s body passively into the opposite joint actions of the joint actions of the target muscle. After all, a joint action is the concentric shortening function of the muscle, so to stretch/lengthen this muscle is to do the opposite of its action(s). For example, if a muscle is a lateral (external) rotator of the hip joint, then bringing the hip joint into medial (internal) rotation would lengthen it. If instead the muscle is a medial rotator of the hip joint, then we would lengthen it by laterally rotating the hip joint.
The piriformis attaches from the internal surface of the sacrum to the greater trochanter of the femur (Image 2). Therefore, to stretch it, all we need to do is visualize the attachments of the muscle and then move the client’s body such that the femoral attachment of the muscle moves away from the sacral attachment. Alternatively, we can explore stretching the piriformis from the point of view of doing the opposite of its joint actions. However, this can be a bit complicated because the line of pull of the piriformis, and therefore its joint actions, can change when the position of the hip joint changes.

Anatomic Position

When the hip joint is in neutral anatomic position, the line of pull of the piriformis crosses posterior to the hip joint (Image 3A, page 70). Therefore, it is a lateral rotator of the thigh at the hip joint and is stretched by medially rotating the thigh at the hip joint.

Because the piriformis can also abduct the thigh at the hip joint, it is important when stretching it to have the thigh adducted (or at least have the thigh in a neutral frontal plane position and not abducted).

The Piriformis and Piriformis Syndrome

The piriformis is one of the six deep lateral rotators of the hip joint. However, because of its attachment to the sacrum and its relationship to the sciatic nerve, the piriformis is considered to be the most important muscle of this group for manual therapists and movement professionals.
Piriformis syndrome occurs when the piriformis is hypertonic (tight) at baseline tone and compresses the sciatic nerve as the nerve passes between the piriformis and the neighboring superior gemellus. There is a lot of fuss about the fact that in approximately 15 percent of individuals, the relationship of the sciatic nerve to the piriformis is different: part or all of the sciatic nerve can travel through the piriformis or superior to it, between the piriformis and gluteus medius. However, an argument can be made that these variations are not more likely to cause compression of the sciatic nerve than the usual presentation. This is because, with these variations, the sciatic nerve is less likely to be compressed since it is actually farther from the pelvic bone, a much harder structure than a tight muscle.
Regardless of the presentation, if the piriformis is sufficiently tight, the sciatic nerve can be compressed. This compression would create the symptoms of sciatica, similar to those that would occur if compression of the nerve roots of the sciatic nerve were compressed by a pathologic disc.

Hip Joint Flexed

When the thigh is flexed at the hip joint to 90 degrees, the line of pull of the piriformis moves to the anterior side of the joint (Image 3B). Therefore, the piriformis becomes a medial rotator of the thigh at the hip joint; consequently, stretching it is accomplished by laterally rotating the hip joint.
When the thigh is flexed at the hip joint to 90 degrees, the piriformis can also be described as a horizontal abductor of the thigh at the hip joint. Therefore, the piriformis can be stretched by horizontally adducting the thigh at the hip joint.

Stretching Protocols for the Piriformis

Given that the piriformis has multiple possible joint actions, there are many choices when it comes to stretching it. Following are some of the more common protocols that are used to effectively stretch the piriformis.

Prone Position

When the client is prone, the hip joint is in anatomic position; therefore, the piriformis is a lateral rotator at the hip joint and would be stretched with medial rotation. Because it is difficult to rotate the client’s thigh by directly contacting it, the (lower) leg is used as a lever to rotate the thigh (see Using the Leg as a Lever to Rotate the Thigh, below). To do this, the therapist stands to the side of the client. The client’s leg is flexed at the knee joint to 90 degrees, and the therapist contacts the client’s distal leg. The client takes a breath in, and then—as the client exhales—the therapist brings the distal leg outward, which brings the thigh into medial rotation at the hip joint, stretching the piriformis (Image 4). Because the reverse closed-chain action of the piriformis is to contralaterally rotate the pelvis at the hip joint, the therapist stabilizes the pelvis with the other hand by pressing on the opposite-side (contralateral) posterior superior iliac spine (PSIS). One precaution when using this stretching protocol is that using the leg as a lever to rotate the thigh torques the knee joint, so this protocol is not recommended if the client has a knee pathology.

Note: Bringing the client’s distal leg outward may seem counterintuitive to medially rotate the thigh, but keep in mind that rotation is always named for where the anterior surface of the body part orients. When the leg is brought outward, the anterior surface of the thigh orients inward/medially.

Using the Leg as a Lever to Rotate the Thigh

Because of the soft tissues that surround the femur, it is logistically difficult to directly contact the thigh to rotate the femur. Instead, the (lower) leg is usually used as a lever to rotate the thigh/femur at the hip joint. This is extremely efficient but does place a torque (rotational force) into the knee joint. For this reason, if the client has an unhealthy knee, any protocol that uses the leg as a lever to stretch the piriformis is either precautioned against or contraindicated.

Stretching and Breathing

Many breathing protocols are recommended when stretching the client, especially when neural inhibition techniques are used. However, there is one breathing guideline that is universally observed: the client should be exhaling when a stretch force is applied to the body. This is because stretching is best accomplished when the client is relaxed, and exhaling best facilitates client relaxation.

Supine Position—Lateral Rotation

There are many ways the piriformis can be stretched when the client is supine. Perhaps the best known protocol is the stretch that is sometimes referred to as the figure-4 stretch because the positioning of the lower extremities resembles the numeral 4.
Using the figure-4 stretch protocol, the client’s hip joint is flexed and laterally rotated, and the knee joint is flexed to 90 degrees. The therapist then places a force into the client’s (lower) leg, using it as a lever to laterally rotate the thigh at the hip joint, thereby stretching the piriformis. The distal thigh can also be contacted to add to the lateral rotation force. As discussed earlier, when the thigh is flexed to 90 degrees, the piriformis becomes a medial rotator and is therefore stretched with lateral rotation. There are a number of ways the client can be contacted when performing this stretch (Images 5A–5C).

Note: As with the prone stretch, because the leg is used as a lever to achieve the stretch, this protocol is precautioned against or contraindicated if the client has an unhealthy knee joint.

Supine Position—Horizontal Adduction—Pushing

Because the piriformis becomes a horizontal abductor when the thigh is first flexed to 90 degrees, it can be stretched with horizontal adduction—in other words, bringing the thigh across the front of the client’s body. This protocol is usually performed by the therapist standing to the side of the client and pushing the thigh into horizontal adduction (Image 6).
It is important when performing this stretch that the client’s pelvis remains on the table; otherwise, the stretch will move into the lumbar spine and be lost for the piriformis. Keeping the pelvis on the table is achieved by pushing across the table but also somewhat down toward the floor.
An advantage to this stretching protocol is that the therapist can contact directly on the client’s thigh instead of the (lower) leg. Therefore, this stretch can be performed even if the client has an unhealthy knee joint.

Supine Position—Horizontal Adduction—Pulling

Another way the supine client’s piriformis can be stretched into horizontal adduction is for the therapist to stand on the opposite side of the table from the side of the piriformis being stretched and pull the client’s thigh into horizontal adduction instead of pushing it. The advantage to this approach is that the therapist can use their body weight to create the stretch.

The client is supine with the hip joint flexed to 90 degrees, and the knee joint flexed. The therapist wraps his cephalad axilla (the axilla, or arm pit, closer to the client’s head) around the  client’s knee. The therapist has a very stable position because both hands are on the table, both feet are well grounded on the floor, and both thighs are braced against the table.
To perform the stretch, the therapist simply sinks downward by bending his lower extremity joints and dropping his body weight down on the client’s distal thigh, bringing it into horizontal adduction to stretch the piriformis. As with the pushing method, it is important to keep the pelvis down on the table (Image 7A). If the client’s pelvis does lift from the table, then the therapist simply adjusts the angle in which they drop down.
In addition to having the advantage of using body weight to create the stretch, this protocol allows the therapist’s hands to be free, if needed. Having the hands free can be extremely valuable to help relieve pinching pain the client often experiences in the proximal anterior thigh when a horizontal adduction stretch is performed. This pain is usually caused by compression of proximal hip flexor musculature that is tight, anywhere from the tensor fasciae latae laterally to the adductor longus medially. It can also be caused by bony impingement compression at the anterior aspect of the hip joint. Having the hands free allows the therapist to wrap their finger pads around the proximal anterior thigh and contact any tight hip flexor musculature that might be present; then, by leaning their body weight back, traction and open the region, thereby alleviating the pinching compression (Image 7B).
    
Note: The therapist must combine leaning back to open the joint, with dropping down with body weight to stretch the piriformis. A little practice might be required to become proficient with this approach, but it is well worth it for the efficacy and comfort of this protocol.

As with the supine horizontal pushing protocol, this stretch can be performed if the client has an unhealthy knee joint because the thigh is contacted directly instead of the client’s leg. However, if any pressure is transmitted into the knee joint and discomfort does occur, then a variant position is to drape the client’s leg around the therapist’s trunk, allowing it to rest there and be supported (Image 7C).

Note: For the female therapist, if either the position shown in Image 7A or 7C causes contact between the client’s thigh and the therapist’s breast tissue, this can be remedied by the therapist rotating her trunk away from the client.

Supine Position—Mixing Lateral Rotation with Horizontal Adduction

If the supine client’s piriformis can be stretched with lateral rotation and it can be stretched with horizontal adduction, then these two motions can be combined into one stretching protocol. To perform this protocol, the therapist stands on the same side of the table as the piriformis being stretched. The client’s foot is placed flat on the table on the other side of the client’s other lower extremity. This position laterally rotates and horizontally adducts the client’s thigh at the hip joint. The therapist then pushes on the client’s distal thigh, further horizontally adducting it (Image 8). As with the pure horizontal adduction approaches, the angle of force should be horizontal and slightly downward so the client’s pelvis remains on the table. An advantage to this stretching protocol is that the likelihood that the client will experience pinching pain in the anterior hip flexor region is decreased compared to the pure horizontal adduction approaches.

Pin and Stretch Technique

As with the stretches shown so far, the pin and stretch technique is a mechanical stretch that works by lengthening the target muscle. However, the advantage to pin and stretch is that it allows the therapist to focus the stretch to one region (one end) of the muscle that contains hypertonic tissue; for example, a myofascial trigger point. This is accomplished by placing a pin somewhere along the course of the target muscle; then, one attachment of the muscle is brought away from this stabilization pin (Image 9).
The stretch creates a line of tension that spreads along the muscle from the attachment that is moved until the pin is reached. In this manner, pin and stretch focuses the stretch to the region of the muscle between the attachment that is moved and the placement of the pin. Generally, pin and stretch technique is most effective when the pin is placed directly next to the hypertonic tissue, on the “other” side from the attachment that is moved.

Neural Inhibition Techniques

As described earlier, stretching is essentially a mechanical process of making a soft tissue longer. However, a neurologic effect can also be added. This is done by adding a neurologic reflex to the stretching protocol. The neurologic reflex inhibits the tone of the muscle so the stretch movement can be greater than by simply mechanically lengthening it. There are two neurologic reflexes that can be used to facilitate a stretch: Golgi tendon organ (GTO) reflex and reciprocal inhibition (RI) reflex.

Contract Relax (CR) Technique.

When the GTO reflex is used, the technique protocol is known as contract relax (CR) stretching. It can also be called post-isometric relaxation (PIR) stretching. And it is often referred to as proprioceptive neuromuscular facilitation (PNF) stretching.
It should be noted that CR stretching technique has classically been stated to utilize the GTO reflex. However, there is controversy as to whether the GTO reflex is the underlying neuromechanical reflex for CR stretching technique. With this controversy in mind, we will address this technique as if the GTO reflex is the neurologic reflex at play.
Although there are variations with how CR stretching is performed, it is classically done with the following steps.

Note: One repetition of these steps is shown for the right-side piriformis with the client supine, and the therapist pushing the thigh into horizontal adduction at the hip joint (Images 10A–10C).

1. The therapist stretches the piriformis to tissue tension barrier (Image 10A).
2. The client isometrically contracts the piriformis against the therapist’s resistance, for a count of approximately 5–8 seconds, with approximately 30 percent of maximum force (Image 10B). The isometric contraction of the piriformis is stated to engage the GTO reflex, thereby inhibiting the piriformis.
3. The client relaxes, and the therapist stretches the piriformis to its new tissue tension barrier position, stretching it further than would otherwise be possible with only a pure mechanical stretch (Image 10C).
4. This is repeated for a total of 3–4 repetitions, with each successive repetition beginning from the position where the previous repetition finished.
5. Breathing protocol can vary, but the most important breathing guideline is that the client breathes out when the stretch force is added in each repetition.
Agonist Contract (AC) Technique. When the reciprocal inhibition (RI) reflex is used, the technique protocol is known as agonist contract (AC) stretching. It is sometimes called antagonist contract stretching instead (still abbreviated as AC). And, it is often referred to as proprioceptive neuromuscular facilitation (PNF) stretching.
Note: Because the term PNF can be applied to both CR and AC stretching techniques, confusion can occur. For this reason, I prefer to avoid using the term PNF and instead use the simpler terms CR and AC stretching techniques.

AC stretching is classically performed with the following steps.

Note: One repetition of these steps is shown for the right-side piriformis with the client supine, and the therapist pushing the thigh into horizontal adduction at the hip joint (Images 11A–11C).

1. From a neutral starting position (Image 11A), the client actively moves into the position of stretch by concentrically contracting horizontal adduction musculature (musculature that is antagonistic to the piriformis, hence the name antagonist contract) (Image 11B). The concentric contraction of horizontal adduction musculature (agonist musculature of the movement, hence the name agonist contract) engages the RI reflex, thereby inhibiting the piriformis (because it is a horizontal abductor).
2. The client relaxes, and the therapist further stretches the client into horizontal adduction (Image 11C).
3. The therapist passively brings the client back to the starting position (Image 11A).
4. This is repeated for a total of 8–10 repetitions, with each successive repetition beginning from the same starting position.
5. Breathing protocol can vary, but, as discussed earlier, the most important guideline is that the client breathes out when the stretch force is added in each repetition.
Contract Relax Agonist Contract (CRAC) Technique. If CR and AC stretching techniques can each be performed, it stands to reason that both techniques can be performed together, thereby gaining the inhibition of both underlying neurologic reflexes. These two techniques can be combined in different ways, but following is one method of doing so—performing first CR and then AC techniques.
Combining the CR and AC stretching techniques is called contract relax agonist contract (CRAC) stretching.

Note: One repetition of these steps is shown for the right-side piriformis with the client supine, and the therapist pushing the thigh into horizontal adduction at the hip joint (Images 12A–12D).

1. From a neutral starting position (Image 12A), the client isometrically contracts the piriformis against the resistance of the therapist (this is the CR step that is said to engage the GTO reflex) (Image 12B).
2. The client actively moves into the position of stretch by concentrically contracting horizontal adduction musculature that is antagonistic to the piriformis (this is the AC step that engages the RI reflex) (Image 12C).
3. The client now relaxes, and the therapist further stretches the client into horizontal adduction (taking advantage of both neurologic reflexes) (Image 12D).
4. The therapist passively brings the client back to the starting position (Image 12A).
5. This is repeated for a total of 3–5 repetitions, with each successive repetition beginning from the same starting position.
6. Breathing protocol can vary, but, as discussed earlier, the most important guideline is that the client breathes out when the stretch force is added in each repetition.

As we can see, there are many protocols for stretching the piriformis, from purely mechanical stretches (applied broadly across the entire muscle), to pin and stretch technique (mechanical, but focuses the stretch to a specific region of the muscle), to the addition of neural inhibition techniques. Because of the tremendous importance of the piriformis, it is important for the therapist to gain expertise and be well versed in a variety of protocols. Adding stretching into a clinical orthopedic manual therapy (COMT) treatment session increases its effectiveness. And, because stretching is more effective if the tissue is first warmed up, stretching the piriformis should be done after the muscle is first warmed up with heat and/or massage.