Key Point

• The beauty of applying the hill and valley approach to palpation of the hip flexor musculature is that the hip flexor muscles form an alternating contour of hill, valley, hill, valley, etc.

When teaching muscle palpation, there is often a rubric that is followed. We begin by learning the attachments of the target muscle so we know where to place our palpating fingers. We then ask the client to contract the muscle so it hardens, thereby becoming more easily palpable. And if we can find a joint action of the target muscle that is different from the joint actions of adjacent musculature, our target muscle will be the only muscle that contracts and becomes hard, soft tissue amidst a sea of soft, soft tissues. This way, we can not only palpate it, but palpate and discern it from adjacent musculature. Once found, we can palpate the entirety of the muscle so we can then assess it.

Palpation of the Hip Flexors

This rubric is effective and can be used for any muscle in the body. It requires knowing the attachments and actions of the target muscle as well as the attachments and actions of the adjacent musculature. If we apply this rubric to flexor musculature of the anterior hip joint, we can work our way from the tensor fasciae latae (TFL) laterally to the adductor magnus medially (Image 1A and 1B). With the client supine,¹ and palpating immediately distal to the inguinal ligament, we can carry out this palpation approach as follows.

TFL

Find the anterior superior iliac spine (ASIS) and drop immediately distal and slightly lateral. Now ask the client to medially rotate the thigh at the hip joint and then gently flex the thigh at the hip joint. The TFL will engage and pop, and we can discern it from the nearby rectus femoris of the quadriceps femoris group as well as the nearby sartorius (Image 2). 

Rectus Femoris

Staying close and parallel to the inguinal ligament, drop immediately medial to the TFL and you should be on the rectus femoris. To confirm this, ask the client to extend the leg at the knee joint. This will engage the rectus femoris, but not the nearby TFL or sartorius (Image 3).

Sartorius

Drop immediately medial to the rectus femoris and you should be on the sartorius. To confirm, ask the client to laterally rotate and abduct the thigh at the hip joint, and slightly flex the leg at the knee joint. The sartorius will engage and pop, but the adjacent muscles will remain relaxed (Image 4).

Iliacus

Now, drop immediately medial to the sartorius and you should be on the iliacus. The iliacus is challenging to have its engagement isolated (because its joint actions are essentially identical to those of the adjacent muscles), so I like to continue palpating medially until I find the psoas major, then return laterally, and whatever is between the psoas major and sartorius will be the iliacus.

Psoas Major

To find the psoas major, look for the first tissue that is medial to the sartorius and engages with gentle flexion of the trunk at the spinal joints (Image 5). The psoas major is the only hip flexor that crosses the spinal joints, so this joint action should yield an isolated engagement of the psoas major. Once found, return laterally for the iliacus as previously mentioned.

Pectineus

Drop immediately medial off the psoas major and you will be on the pectineus. Similar to the iliacus, the pectineus is challenging to have its engagement isolated, so I like to continue palpating medially until I find the adductor longus, then return laterally. Whatever is between the adductor longus and psoas major will be the pectineus (Image 6).

Adductor Longus

The adductor longus has the most easily palpable proximal tendon of all the hip flexors and is usually clearly palpable even when it is relaxed. Once located, return laterally for the pectineus. But if we did want to engage it to make it contract and pop, then we ask the client to gently adduct the thigh at the hip joint (Image 7).

Adductor Brevis

The adductor brevis is the most challenging and variable of the hip flexors. It can be wholly deep to the adductor longus, and therefore not discernible from the more superficial adductor longus. And sometimes, there is some superficial exposure of the adductor brevis on the lateral side of the adductor longus, between it and the pectineus. But most often, there is a small amount of superficial exposure of the adductor brevis lateral (and at this point, it could be said to be posterior) to the adductor longus. However, because the longus and brevis share all the same joint actions, it’s not possible to find a different joint action to discern between them.

Gracilis

Whether it is the adductor longus or brevis, drop immediately medial (posterior), and you should be on the gracilis. To discern the gracilis, ask the client to flex the leg at the knee joint and only the gracilis will engage, given that the adjacent muscle on each side does not cross the knee joint and, therefore, will not engage with knee flexion (Image 8).

Adductor Magnus

Once the gracilis has been found, we drop immediately posterior off it and will be on the adductor magnus. To engage it, ask the client to extend the thigh at the hip joint and the adductor magnus will engage (the anterior head of the adductor magnus is a hip flexor, but its posterior head does hip extension), but the gracilis will not (Image 9).

Medial Hamstrings

Locate the medial hamstrings (semitendinosus and semimembranosus) by asking the client to flex the leg at the knee joint. This will engage the hamstrings but not the adductor magnus. Given that the exercise in this article is to palpate and discern the hip flexors, we are locating the medial hamstrings only as a means of locating the posterior border of the adductor magnus.

Hill and Valley Approach

As I hope this rubric shows, we can use joint actions as a means of palpation to locate and discern our target muscle. Indeed, this is how muscle palpation is classically taught and I wholly approve of this approach and use it as my default guideline with palpation assessment. However, this approach can be costly timewise, so I would like to offer the possibility of a different approach to muscle palpation.

When possible, if a target muscle can be palpated and discerned simply by knowing its location and using its contour to be confident that we are on it, it saves time and energy and facilitates the job of muscle palpation. This contour approach to muscle palpation can be used when palpating the hip flexor musculature, and when used here, I like to call it the hill and valley approach. Instead of spending time asking the client to engage the target muscles, we can simply discern each hip flexor muscle by its contour: If the contour is rounded and prominent, it is a hill; if it is flat and sits recessed between two hills, it is a valley. 

The beauty of applying the hill and valley approach to palpation of the hip flexor musculature is that the hip flexor muscles form an alternating contour of hill, valley, hill, valley, etc. We begin with the TFL, which has a rounded contour and is clearly a hill. We drop immediately medial off it and the rectus femoris sits in a valley between the rounded hills of the TFL on the lateral side and the sartorius on the medial side. From the hill of the sartorius, we drop medially off it, and we have the valley of the iliacus, which sits between the hills of the sartorius on the lateral side and the psoas major on the medial side. The psoas major is another hill, and immediately medial to it is the valley of the pectineus that sits between the hills of the psoas major on its lateral side and the adductor longus on its medial side. The adductor brevis is variable but often sits as a valley between the hills of the adductor longus on its lateral side and the gracilis on its medial (posterior) side. The gracilis is a hill, and immediately posterior to it is the adductor magnus, which is a valley that sits between the hills of the gracilis on its anterior side and the medial hamstrings that sit on its posterior side. 

So, we have TFL (hill), rectus femoris (valley), sartorius (hill), iliacus (valley), psoas major (hill), pectineus (valley), adductor longus (hill), adductor brevis (valley), gracilis (hill), adductor magnus (valley), and medial hamstrings (hill again) as the posterior border of the adductor magnus (Image 10).

Or, looking at these muscles as couplets of two hills with a valley between, we have TFL and sartorius as hills, with the rectus femoris as the valley between them (Image 11A); sartorius and psoas major as the hills, with the iliacus as the valley between them (Image 11B); psoas major and adductor longus as the hills, with the pectineus as the valley between them (Image 11C); adductor longus and gracilis as the hills, with the adductor brevis as the valley between them (Image 11D); and gracilis and medial hamstring muscles as the hills, with the adductor magnus as the valley between them (Image 11E).

When it comes to the rubric of having the client engage the target muscle to locate it versus simply using the contour approach, I recommend new practitioners work with the engagement approach because it is confirmation that you are, in fact, on the target muscle. But once you are more experienced, simply having the knowledge of the location and contour of the target musculature is often enough to know with confidence that you have located it. With either approach, once located, the target muscle can then be assessed. 

Finding the Difference

When we ask the client to contract the target muscle by doing one of its joint actions (given that most muscles have more than one joint action), the art of muscle palpation is determining which action to choose. Or, perhaps better put, which oblique-plane joint function to choose, given that muscle function does not always fall neatly into cardinal-plane joint actions.

For our example, when palpating the hip flexor muscles, given that all hip flexors do hip joint flexion, it is not useful to ask the client to try to do hip flexion because all the hip flexors will likely engage, making it difficult to discern our target muscle from the adjacent musculature. What we need is to have the target muscle be the only hard, soft tissue, amidst a sea of soft, soft tissues. Having the target muscle and the adjacent muscles all contract will not accomplish this. Therefore, we need to find a difference between our target muscle and the adjacent muscles. For this reason, we ask for medial rotation when palpating the tensor fasciae latae (TFL), for knee extension when palpating the rectus femoris, and for trunk flexion when palpating the psoas major, to cite a few examples. The art of muscle palpation when asking the client to engage the target muscle is learning how to choose the best joint action/oblique-plane function of the target muscle that is most different from the adjacent musculature.

Note

1. Images 2–9 demonstrate the client lying on the table supine with their right thigh on the table and their (lower) leg hanging off the table. Ideally, their left hip and knee joints should be flexed with the left foot on the table so the pelvis is stabilized. However, this was not done for the sake of the camera view. The palpation protocol for these muscles could also be done with the client lying supine with both lower extremities on the table.