It is important to completely visualize the bilateral lower extremities during the examination. This is best accomplished by having the patient disrobe or change into examination shorts prior to beginning the evaluation. During inspection careful attention should be paid to signs of bruising, swelling, and skin changes that may suggest underlying vascular or neurologic disease. Visible erythema and swelling associated with pain and increased warmth are the classic signs of inflammation and should prompt the clinician to consider inflammatory causes of leg pain. Inflammatory causes of leg pain can be localized or systemic. Leg pain in the presence of skin rashes and nail abnormalities are also suggestive of possible systemic inflammatory conditions. Scars or wounds on the legs should be noted and correlated with the past medical and surgical history.

If bruising is found, note the location, size, distribution, and color. Location and distribution of ecchymosis can suggest the location of the injury and its depth. The color of the bruising suggests the acuity of the bleeding. Upon extravasation of blood, hemoglobin begins to degrade in a sequential fashion, giving rise to progressive change in color and eventual resolution of bruising by 2 weeks. In this way, the color of the bruise can be used to age the injury: red-blue color (0–5 days), green color (5–7 days), yellow color (7–10 days), and golden-brown color (10–14 days). It should be noted that bruising or contusion refers to subcutaneous bleeding that has a traumatic etiology. Ecchymosis is a more general description of subcutaneous bleeding greater than 1 cm and may not be traumatic in etiology. Nontraumatic causes of ecchymosis include coagulopathies. Subcutaneous bleeding less than 1 cm in diameter is either called petechia (< 3 mm) or purpura (3 mm–1 cm), which are associated with platelet disorders or vasculitis, respectively. Bruising is easier to identify in patients with light skin complexions. It is common for the blood to travel along soft tissue planes which often results in migration of the bruising over time.

If calf swelling is present, take note if the calf swelling is unilateral or bilateral. Unilateral calf swelling is indicative of localized pathology whereas symmetrical swelling suggests a systemic cause. Inspection can also help determine if the swelling can be classified as pitting or non-pitting edema. Indentations from socks, shoes, or other tight-fitting clothing can be useful in detecting pitting edema. Non-pitting edema is caused by lymphedema. Pitting edema has a variety of local and systemic causes. Acute unilateral pitting edema of the leg is often due to deep venous thrombosis (DVT), cellulitis, a ruptured bakers cyst, or trauma.

Stigmata of chronic vascular disease should also be sought on inspection . Arterial peripheral vascular disease should be suspected if there are well-demarcated ulcers or non-healing lesions in the distal extremity along the ground contact areas, erythema of the foot in a dependent position which changes to pallor with elevation, and skin that is shiny, dry, and atrophic with absence of hair. Chronic venous disease is suspected on inspection if chronic soft, pitting edema is seen in the ankle and evidence of dependent varicosities of the leg with hyperpigmented skin and venous ulcerations over medial malleolus.

Inspection of the legs may also reveal stigmata of neuropathy. Thin ankles and legs along with deformities of the arch and toes can suggest hereditary neuropathies such as Charcot–Marie–Tooth (CMT) disease. Complex regional pain syndrome type 1 is associated with visible swelling and discoloration of the affected leg.

Screening for leg length should be done on inspection. A reasonable screening test of leg length symmetry can be done by observing the patient from behind while comparing the relative height of popliteal and gluteal creases. If you suspect a clinical relevant difference in leg length, additional clinical tests should be performed for further assessment. Specific examination techniques for leg length are discussed below.

Observation of the lower extremities during functional movement is important. At a minimum, inspection should be done on standing and walking. In addition, observation while running or other relevant movements can greatly aid the clinical evaluation. Evaluation of gait and station are covered separately in the next section.

Examination of gait and station should be incorporated with the examination of the lower extremity. Because of the functional role the muscles of the posterior leg have in standing and ambulating, injuries to these muscles are often most noticeable during the evaluation of gait and station. Correlating abnormalities in gait and station to the underlying pathology requires an understanding of the normal and abnormal presentation. It should be noted that abnormities of gait and station not only can be the result of pathology but also can be causative factor in precipitating the injury. Therefore, although evaluation of gait and station can help the clinician in the diagnosis of acute muscle injuries in the posterior leg , the detailed evaluation of gait is most helpful in investigating chronic or recurrent issues that may be caused by underlying biomechanical abnormalities.

Station or stance position is evaluated by observation of the standing patient. Normal station should reveal a balanced body posture over the center of gravity and symmetrical alignment of the lower limbs and feet. In neutral stance position, alignment of the lower limb should reveal a weight-bearing line in a sagittal plane through the anterior superior iliac spine, patella, and second metatarsal of each lower extremity. The heel should be perpendicular to the forefoot and in line with the tibia. The knee should be fully extended with slight valgus alignment. The subtalar joint and hips should be in a neutral position. The pelvis should exhibit a slight anterior tilt. Significant deviations from ideal stance position suggest structural abnormalities or compensations that may lead the clinician to the diagnosis or suggest the cause of the presenting complaint (Table 6.1) . When these common clinical associations are subject to evaluation by evidence-based methods the conclusions reached have been very limited [2, 3].

Gait is classically described by its two component actions called the stance phase and the swing phase. The stance phase refers to the portion of gait when the foot is on the ground, while the swing phase refers to the portion of gait when the foot is no longer in contact with the ground. The repeated progression of stance phase through swing phase produces the motion of walking and running called the gait cycle. The phases of gait are further divided into component actions. The stance phase is subdivided into heel strike, mid-stance, and push-off. The swing phase is subdivided into acceleration, mid-swing, and deceleration.

The phases of running and walking are similar. Running is defined by the addition of a flight phase between stance phases in which neither foot is in contact with the ground. While walking, 60 % of the gait cycle is spent in stance phase and 40 % in swing phase. During running, the portion of time spent in stance phase decreases with increasing running speed. In addition, running is associated with greater ROM of the pelvis, hip, and knee as well as a narrower base of gait when compared to walking.

Examination of gait can begin even before the formal exam. Observation of the patient as they ambulate through the office is most likely to reveal natural movement patterns and can quickly identify an obvious limp or the use of assistive devices. During formal examination of gait, try to identify which phase of gait and component motion is pathologic. Most abnormalities will be present in stance phase where the extremity is susceptible to the liabilities of weight bearing. Patients with muscle weakness in the gastrocnemius , soleus, and flexor hallucis longus or Achilles rupture may exhibit a flat foot gait with no or limited push-off. Gastrocnemius strains may result in the patient adopting a gait characterized by excessive knee flexion and ankle plantar flexion in an attempt to splint the affected muscle. A bouncy gait suggests early heel lift from ankle equinus or heel pain. Compensations related to ankle equinus lead to posterior leg muscles strains, Achilles tendon injuries, shin splints, and stress fractures. Patients with fractures or other severe acute trauma will have pain in all phases of gait and are likely to either not bear weight on the affected extremity or spend as little time as possible in stance phase.

During mid-stance, as the body passes over the weight-bearing limb, the pelvis and trunk shift laterally over the weight-bearing side and drop slightly on the non-weight-bearing limb. Excessive lateral displacement during mid-stance is caused by gluteus medius weakness and results in a gluteus medius or abductor lurch gait. The Trendelenburg test evaluates the function of the gluteus medius in maintaining dynamic pelvic stability in single-leg, weight-bearing stance. The test is performed by observing the patient from behind while they are standing in double-leg stance and then in single-leg stance alternating between each leg. A positive test occurs when the pelvis does not elevate on the unsupported side during single-leg, weight bearing stance. A positive test indicates inadequate force is being generated by the gluteus medius on the stance leg to maintain dynamic pelvic stability during single-leg, weight bearing stance. This can lead to biomechanical abnormalities which increase likelihood of injuries. Inadequate gluteus medius force generation can be caused by poor gluteus medius development, poor activation sequence, nerve root mediated weakness, and anatomical variations that functionally shorten the muscle.

Excessive subtalar pronation can lead to overload of the soleus , gastrocnemius, and tibialis posterior during dynamic supination and plantar flexion. This can lead to excessive muscle tightness and soreness. In addition, overload from excessive subtalar pronation can predispose the muscles of the posterior leg to strain and tendon damage. Moreover, excessive muscle overload can cause muscular hypertrophy that can contribute to the development of compartment syndrome.

Excessive supination of the subtalar joint suggests contracture of the gastrocnemius, soleus, and tibialis posterior, structural abnormalities of the foot or weak peroneals. Excessive supination limits mobility of the foot resulting in reduced ability to attenuate force during the gait cycle and increased risk for stress fractures of the leg and foot.