Traumas to the iliopsoas can affect the proximal part upstream of the myotendinous junction. It is a rare lesion, of the muscle only, in the lumbar fossa or the iliac fossa. Clinicians should be particularly attentive when this trauma occurs in patients with hemophilia, coagulation disorder or those taking an anticoagulant treatment. The heavily vascularized and innervated environment will result in a particular clinical picture. They start suddenly, for example with an uncontrolled slide or blocked hip flexion. The symptomatology is unclear from the outset with deep pains, and lack of movement on palpation. Complications may appear rapidly due to the extensive hematoma which develops in the muscle, with psoitis [1] causing permanent flexion of the hip and cruralgia with superficial loss in sensitivity on the anterior aspect of the thigh and partial motor loss in the quadriceps. If diagnosis and therapy are not performed in time, post-traumatic ossifying myositis may occur [13].

This is the most common location although it has very rarely been documented in the literature. In a previous work we assessed the sensitivity of clinical signs in a series of 33 cases [14]. The reason for consultation is the appearance of anterior hip pain which is either sudden (45 %) or rapidly progressing (55 %). It occurs in the middle of an activity, particularly when kicking a ball or changing foot position in team sports, or a violent draw stroke in kayaking. Team sports represent 69 % of cases.

Limping and psoitis are initially present in one third of cases and five times out of six the lesion affects the dominant side. In 50 % of cases, these unclear symptoms are replaced after a few days by an insidious picture that systematically evolves to chronic mode if the diagnosis is not done initially. Average treatment time is 5 days when performed early, rising to 3 months on average for injuries treated late.

The examination starts with a search for negative signs. Hip joint mobility is conserved. No clicking is observed. Palpation of the bony structures is painless, particularly on the anterior superior iliac spine (avulsion) and the ischiopubic ramus (stress fracture). The neurovascular examination is normal. There is no hernia.

The pain is in the groin, limiting the rear step. Pain on stretching is only present in 18 % of cases. It should be located with the patient prone, the clinician’s hand blocking pelvic retroversion, and the patient’s hip in slight abduction (Fig. 15.2).

In 78 % of cases the pain occurs in contraction against resistance in the supine position, with the knee in extension and the hip in slight abduction (Fig. 15.3). This sign is all the more valuable if there is no pain when the knee is extended against resistance, bringing into play another hip extensor, the anterior femoral muscle.

Pain on palpation, which is sharper but far less specific, is present in 89 % of cases. It should be located with the hip semi-flexed, just outside the femoral neurovascular bundle and inside the sartorius muscle.

Similarly, pain should systematically be located by contracting the neighboring muscles, in particular the external adductor and obturator muscles which may also have an intrinsic lesion. The examination is completed by locating stiffness in the anterior pelvic chains (53 % of cases), a manifestation of athletic pubalgia (16 % of cases) or lumbago (13 % of cases) or other differential diagnoses as shown in Table 15.1 (Sect. 15.7).

Tendon disinsertion, combined or not with an avulsion fracture of the lesser trochanter, is a rare accident which is most likely to occur to older men. These accidents are sudden, caused when a movement is countered by an opponent or by a sharp, uncontrolled change in foot position. Football (soccer) is the sport that produces it most commonly [15]. Anterior hip pain is immediate and disabling. It leads to retraction. The athlete is incapable of raising the lower limb when lying down. Active hip flexion is impossible, particularly in the sitting position. A full clinical study of the hip is disrupted by the extent of the initial pain and should be resumed after a few days of rest. At this stage the examination may find bruising of the anterior-medial thigh, heading down towards the knee.

Adolescents may present a similar acute picture with apophyseal avulsion or a chronic picture with apophysitis during growth. Boys who do football, athletics and skating seem to be the most affected [16]. Healing occurs by fusion of the secondary ossification centers over 3–4 months with a total break from sport.

These are lesions that also concern the myotendinous junction region. This symptomatic clicking corresponds to the sudden movement or even turn [11] of one of the myotendinous parts of the iliopsoas on the iliopectineal eminence when certain movements are made, and is often accompanied by bursitis. These pathologies evoke a conflict which is encouraged by the anatomical context [17]. The patients are young and describe more or less painful snapping during the active switch from flexion to extension of the hip. The symptoms evolve in a fluctuating manner which does not systematically occur at the same time as physical effort. A physical examination should seek to reproduce an audible snapping, with the patient standing during the switch from flexion to extension-abduction-lateral rotation [16]. Passive mobilization of the hip produces no result. Dynamic ultrasound contributes strongly to the diagnosis [11]. Conservative treatment is recommended.