The groin pain that tests do not explain

Groin pain when walking, climbing hills, or rising from a chair is a symptom that frequently causes concern: the inguinal region houses important structures — femoral vessels, lymph nodes, femoral nerve, inguinal canal with hernia. When all tests come back normal, the most common and frequently overlooked diagnosis is iliopsoas syndrome — tension and trigger points in the psoas major and iliacus muscles, which together form the iliopsoas.

The iliopsoas is the main hip flexor. Its unique trajectory — descending along the lumbar spine, crossing the pelvis internally, and inserting at the lesser trochanter of the femur — makes it a deep muscle, inaccessible to superficial physical examination and invisible to conventional ultrasound that evaluates the inguinal region. This inaccessibility makes its dysfunction a rare diagnosis in general practice, despite being extremely prevalent.

Why climbing hills hurts more: iliopsoas biomechanics

  1. Walking on level ground

    In gait on level terrain, the iliopsoas performs moderate hip flexion in each stride — around 20–30° of active flexion. With trigger points in the psoas, this repetitive contraction generates groin pain that worsens with prolonged walking but can be tolerated.

  2. Climbing hills and stairs

    When climbing a hill or stairs, hip flexion increases to 60–90° — requiring maximal contraction of the iliopsoas. It is exactly at this moment that groin pain intensifies and limits movement. Patients describe that "they can walk on level ground, but no longer climb stairs."

  3. Rising from a chair

    The movement of rising from a seated position requires knee extension and, simultaneously, initial hip flexion by the iliopsoas. With the muscle tense, groin pain on rising is the most characteristic symptom — and frequently the first one the patient notices.

  4. Fetal position and relief

    The iliopsoas tends to shorten in positions of prolonged hip flexion (sedentary lifestyle, sitting work). The patient with iliopsoas syndrome frequently sleeps in fetal position with relief — because the muscle is relaxed in that position. Lying supine with legs extended worsens the pain.

  5. Iliopsoas dry needling

    Deep needling of the iliopsoas requires a trained physician: the needle is introduced obliquely through the anterolateral abdominal wall, around the iliac vessels, until it reaches the muscle belly in the retroperitoneal corridor. Electroacupuncture 2–4 Hz for 20 minutes produces immediate relaxation and segmental analgesia of the lumbar plexus.

Epidemiology and clinical context

common
IN SEDENTARY ADULTS
clinical series describe iliopsoas shortening detectable by the Thomas test in a significant share of sedentary individuals, contributing to low back pain and groin pain
frequent
IN CHRONIC LOW BACK PAIN
psoas tension is described as a perpetuating factor in many cases of chronic low back pain — the muscle pulls the lumbar vertebrae anteriorly, increasing lordosis
variable
NUMBER OF SESSIONS
series of deep iliopsoas dry needling with electroacupuncture report pain reduction and gain in hip flexion range, with the number of sessions individualized according to chronicity
a share
OF CASES
a significant share of "groin pain of undetermined cause" with normal imaging may have the iliopsoas as the generator, according to clinical reviews — the exact proportion varies between populations and diagnostic criteria

Recognizing iliopsoas syndrome

Critérios clínicos
08 itens

Typical clinical pattern of iliopsoas syndrome

  1. 01

    Groin or inguinal pain when walking, mainly when climbing hills or stairs

  2. 02

    Pain when rising from a seated position, especially from low chairs

  3. 03

    Sensation of "cramping" or tension in the groin after prolonged walking

  4. 04

    Associated low back pain — mainly when hyperextending the spine

  5. 05

    Difficulty taking long strides or running

  6. 06

    Relief when lying with knees flexed (fetal position)

  7. 07

    Worsens when lying supine with legs straight

  8. 08

    Sensation that "something is stuck" in the groin when getting up

Myths and facts about groin pain

Myth vs. Fact

MYTH

Groin pain is always an inguinal hernia

FACT

Inguinal hernia produces a visible or palpable bulge in the groin that worsens with abdominal effort. Iliopsoas syndrome causes groin pain with hip movement, without a bulge. Inguinal ultrasound with hernia absent and pain reproducible on the Thomas test strongly points to the iliopsoas.

MYTH

The iliopsoas cannot be treated without surgery

FACT

Deep iliopsoas dry needling performed by a physician with specific training can be a relevant conservative alternative — without surgery in most cases, although not all respond. Release of psoas spasm by needling can reduce tension and improve hip flexion range, with variable individual response magnitude.

Clinical pearl: the Thomas test

Treatment protocol

Clinical assessment and Thomas test
1st visit

Thomas test to quantify iliopsoas shortening. Palpation of the femoral triangle (groin): reproduction of pain with deep pressure lateral to the femoral vessels. Lumbar assessment: hyperlordosis associated with psoas shortening. Exclusion of organic causes: hernia, adenitis, urologic or gynecologic pathology.

Deep iliopsoas dry needling
Sessions 1–4

Deep needling (60–80 mm) through the anterolateral abdominal corridor, identifying the iliopsoas belly by tactile feedback. Electroacupuncture 2 Hz for 20 minutes. Combination with points ST-25, ST-36, SP-12, and SP-13 (traditional points in the inguinal region). Immediate improvement of pain and increased stride when walking.

Stretching and strengthening
Weeks 3–8

Guidance on specific iliopsoas stretches: lunge with knee supported, yoga warrior position — performed after needling while the muscle is relaxed. Eccentric strengthening of the glutes (antagonists of the iliopsoas) for muscular rebalancing and prevention of recurrence.

Maintenance and ergonomics
Months 2–3

Breaks every 1 hour of prolonged sitting (sedentary lifestyle is the main factor in chronic psoas shortening). Monthly maintenance sessions for patients with sedentary jobs. Associated lumbar assessment: psoas tension is a perpetuating factor of low back pain that, if not addressed, leads to recurrence of the syndrome.

Frequently asked questions

FREQUENTLY ASKED QUESTIONS · 03

Frequently Asked Questions

When performed by a physician with specific training in anatomy and deep needling, the procedure has an acceptable safety profile reported in specialized pain clinics. Even so, it is not without risks — possible complications include hematoma from vascular puncture and local pain. Correct technique, appropriate patient selection, and contraindication in those using anticoagulants are fundamental. Guiding the procedure with ultrasound adds a margin of safety in selected cases.

Yes. Early-stage hip arthrosis can cause groin pain when walking, very similar to iliopsoas syndrome. The distinction is clinical: arthrosis worsens with internal rotation of the hip and is confirmed by X-ray (joint space narrowing). With normal X-ray and pain that worsens on active flexion but not on rotation, the iliopsoas is the more likely generator.

Most patients with iliopsoas syndrome without chronicity (<6 months) respond in 6–8 sessions. Chronic cases with marked shortening and associated low back pain may require 10–12 sessions for complete resolution, with monthly maintenance in patients with sedentary jobs.