Gait abnormality is a deviation from normal walking (gait). Watching a patient walk is the most important part of the neurological examination. Normal gait requires that many systems, including strength, sensation and coordination, function in an integrated fashion. Many common problems in the nervous system and musculoskeletal system will show up in the way a person walks.

Persons suffering from peripheral neuropathy experience numbness and tingling in their hands and feet. This can cause ambulation impairment, such as trouble climbing stairs or maintaining balance. Gait abnormality is also common in persons with nervous system problems such as cauda equina syndrome, multiple sclerosis, Parkinson's disease, Alzheimer's disease, myasthenia gravis, normal pressure hydrocephalus, and Charcot–Marie–Tooth disease. Research has shown that neurological gait abnormalities are associated with an increased risk of falls in older adults.

Orthopedic corrective treatments may also manifest into gait abnormality, such as lower extremity amputation, post-fracture, and arthroplasty (joint replacement). Difficulty in ambulation that results from chemotherapy is generally temporary in nature, though recovery times of six months to a year are common. Likewise, difficulty in walking due to arthritis or joint pains (antalgic gait) sometimes resolves spontaneously once the pain is gone. Hemiplegic persons have circumduction gait and those with cerebral palsy often have scissoring gait.

This gait pattern is reminiscent of a marionette. Hypertonia in the legs, hips and pelvis means these areas become flexed to various degrees, giving the appearance of crouching, while tight adductors produce extreme adduction, presented by knees and thighs hitting, or sometimes even crossing, in a scissors-like movement while the opposing muscles, the abductors, become comparatively weak from lack of use. Most common in patients with spastic cerebral palsy, the individual is often also forced to walk on tiptoe unless the plantarflexor muscles are released by an orthaepedic surgical procedure.

These features are most typical with the scissors gait and usually result in some form and to some degree regardless of the mildness or severity of the spastic CP condition:

- rigidity and excessive adduction of the leg in swing

- plantar flexion of the ankle

- flexion at the knee

- adduction and internal rotation at the hip

- progressive contractures of all spastic muscles

- complicated assisting movements of the upper limbs when walking.

Since astasis itself is more a symptom than a disease, it is more often seen associated with other signs and symptoms. People who have astasis often experience

- Odd gyrations

- Tightrope balancing deficits (in which a person attempts to balance on a tightrope in order to test balance and motor coordination)

- Near falling deficits (which is a test in which the patient is slightly pushed in order to check their ability to regain posture)

- Exaggerated effort deficits (which is an overcompensation test used to determine motor coordination ability)

- Atypical postures and weakness

- Paralysis

- Jumping fits (in which motor control is partially or totally lost)

- Tremors

One study described a patient with astasis as lying in bed with a normal body posture. When the patient was sitting, he tilted his body to the left. When he was asked to stand up, the patient rotated his trunk axis to the left (left shoulder going backwards), and tilted his body to that same side, showing resistance to passive correction of posture in both of these planes. He was unable to stand and fell backwards and towards the left.

Weakness of the triceps surae muscle has been seen in many patients who have been diagnosed with astasis. This weakness can be caused by a myopathy to that muscle group. The bilateral triceps surae muscle, made up of the gastrocnemius and the soleus, is essential to maintain a straight posture while standing. This indicates that weakness to this muscle is the cause of the swaying and impaired posture in patients with astasis. This weakness is seen regardless of whether somatosensory feedback from the legs is impaired, suggesting it is one of the main causes of astasia without abasia.

Parkinsonian gait (or festinating gait, from Latin "festinare" [to hurry]) is the type of gait exhibited by patients suffering from Parkinson's disease (PD). This disorder is caused by a deficiency of dopamine in the basal ganglia circuit leading to motor deficits. Gait is one of the most affected motor characteristics of this disorder although symptoms of Parkinson's disease are varied.

Parkinsonian gait is characterized by small shuffling steps and a general slowness of movement (hypokinesia), or even the total loss of movement (akinesia) in the extreme cases. Patients with PD demonstrate reduced stride length and walking speed during free ambulation while double support duration and cadence rate are increased. The patient has difficulty starting, but also has difficulty stopping after starting. This is due to muscle hypertonicity.

Patients with Parkinson's disease exhibit gait characteristics that are markedly different from normal gait. While the list of abnormal gait characteristics given below is the most discussed, it is certainly not exhaustive.

Tandem gait is a gait (method of walking or running) where the toes of the back foot touch the heel of the front foot at each step. Neurologists sometimes ask patients to walk in a straight line using tandem gait as a test to help diagnose ataxia, especially truncal ataxia, because sufferers of these disorders will have an unsteady gait. However, the results are not definitive, because many disorders or problems can cause unsteady gait (such as vision difficulties and problems with the motor neurons or associative cortex). Therefore, inability to walk correctly in tandem gait does not prove the presence of ataxia.

Profoundly affected tandem gait with no other perceptible deficits is a defining feature of posterior vermal split syndrome.

Suspects may also be asked to perform a tandem gait walk during the "walk and turn" part of a field sobriety test.

Unlike ataxias of cerebellar origin, Bruns apraxia exhibits many frontal lobe ataxia characteristics, with some or all present.

- Difficulty in initiating movement

- Poor truncal mobility

- Falls due to minor balance disturbances

- Greatly hindered postural responses

- Characteristic magnetic gait, the inability to raise one's foot off of the floor.

- Wide base, poor balance control when in stance

- Short stride

- En bloc turns

Often patients with frontal lobe ataxia may experience minute cognitive changes that accompany the gait disturbances, such as frontal dementia and presentation of frontal release signs (Plantar reflex). Urinary incontinence may also be present.

Bruns apraxia can be distinguished from Parkinsonian ataxia and cerebellar ataxia in a number of ways. Patients typically afflicted with Parkinsonian ataxia typically have irregular arm swing, a symptom not typically present in frontal ataxia. Walking stride in cerebellar ataxia varies dramatically, accompanied by erratic foot placement and sudden, uncontrolled lurching, not generally characteristic of Bruns apraxia.

Scissor gait is a form of gait abnormality primarily associated with spastic cerebral palsy. That condition and others like it are associated with an upper motor neuron lesion.

Myopathic gait (or waddling gait) is a form of gait abnormality.

The "waddling" is due to the weakness of the proximal muscles of the pelvic girdle.

The patient uses circumduction to compensate for gluteal weakness.

Conditions associated with a myopathic gait include pregnancy, congenital hip dysplasia, muscular dystrophies and spinal muscular atrophy

Bruns apraxia, or frontal ataxia is a gait apraxia found in patients with bilateral frontal lobe disorders. It is characterised by an inability to initiate the process of walking, despite the power and coordination of the legs being normal when tested in the seated or lying position. The gait is broad-based with short steps with a tendency to fall backwards. It was originally described in patients with frontal lobe tumours, but is now more commonly seen in patients with cerebrovascular disease.

It is named after Ludwig Bruns.

Gluteal gait is an abnormal gait caused by neurological problems. If the superior gluteal nerve or obturator nerves are injured, they fail to control the gluteus minimus and medius muscles properly, thus producing an inability to tilt the pelvis upward while swinging the leg forward to walk. To compensate for this loss, the leg swings out laterally so that the foot can move forward, producing a shuffling or waddling gait.

Injury to the superior gluteal nerve results in a characteristic motor loss, resulting in a disabling gluteus medius limp, to compensate for weakened abduction of the thigh by the gluteus medius and minimus, and/or a gluteal gait, a compensatory list of the body to the weakened gluteal side.

As a result of this compensation, the center of gravity is placed over the supporting lower limb. Medial rotation of the thigh is also severely impaired. When a person is asked to stand on one leg, the gluteus medius and minimus normally contract as soon as the contralateral foot leaves the floor, preventing tipping of the pelvis to the unsupported side. When a person with paralysis of the superior gluteal nerve is asked to stand on one leg, the pelvis descends on the unsupported side, indicating that the gluteus medius on the contralateral side is weak or non-functional. This observation is referred to clinically as a positive Trendelenburg's sign.

When the pelvis descends on the unsupported side, the lower limb becomes, in effect, too long and does not clear the ground when the foot is brought forward in the swing phase of walking. To compensate, the individual leans away from the unsupported side, raising the pelvis to allow adequate room for the foot to clear the ground as it swings forward.

Tremor is the uncontrollable shaking of an arm or a leg. Twitches or jerks of body parts may occur due to a startling sound or unexpected, sudden pain. Spasms and contractions are temporary abnormal resting positions of hands or feet. Spasms are temporary while contractions could be permanent. Gait problems are problems with the way one walks or runs. This can mean an unsteady pace or dragging of the feet along with other possible irregularities (Stone).

Ataxia is a motor disorder that affects the spinal cord, brain and brainstem. Symptoms of ataxia include tremors, lack of coordination, loss of balance, instability, inaccuracy, clumsiness, gait problems, speech problems, and involuntary eye movements. Medication is the main treatment of ataxia. Some of these medicines include selegiline, amantadine, entacapone, dopamine agonists, and anticholinergics (“Movement Disorders”).

Astasia-abasia refers to the inability to either stand or walk in a normal manner. Astasia refers to the inability to stand upright unassisted. Abasia refers to lack of motor coordination in walking. The term "abasia" literally means that the base of gait (the lateral distance between the two feet) is inconstant or unmeasurable. When seen in conversion disorder, the gait is bizarre and is not suggestive of a specific organic lesion: often the patient sways wildly and nearly falls, recovering at the last moment.

An acquired total inability to stand and walk can be seen in true neurological diseases, including stroke, Parkinson's disease, damage to the cerebellum, Guillain–Barré syndrome, normal pressure hydrocephalus and many others. In normal pressure hydrocephalus, for example, when the condition remains untreated, the patient's gait becomes shortened, with frequent shuffling and falls; eventually standing, sitting, and even rolling over in bed become impossible. This advanced state is referred to as "hydrocephalic astasia-abasia".

Blocq's disease was first considered by Paul Blocq (1860–1896), who described this phenomenon as the loss of memory of specialized movements causing the inability to maintain an upright posture, despite normal function of the legs in the bed. The patient is able to stand up, but as soon as the feet are on the ground, the patient cannot hold himself upright nor walk; however when lying down, the subject conserved the integrity of muscular force and the precision of movements of the lower limbs. The motivation of this study came when a fellow student Georges Marinesco (1864) and Paul published a case of parkinsonian tremor (1893) due to a tumor located in the substantia nigra.

In the third paper published by Paul Blocq, he was trying to determine the neurophysiology behind this disease by relating the cerebral cortex (the decision making) and the spinal cord (the decision executer). His hypothesis was that there would exist an inhibitory influence which exerted and influenced the cortical or spinal centers for standing and walking.

Astasia and/or abasia are associated with the corresponding fears of walking and/or standing, variously called stasophobia, basophobia, stasiphobia, basiphobia, stasobasophobia, stasibasiphobia, etc., sometimes turning into pathological forms, i.e. phobias.

Stomping gait (or sensory ataxia gait) is a form of gait abnormality.

Cerebellar ataxia can occur as a result of many diseases and presents with symptoms of an inability to coordinate balance, gait, extremity and eye movements. Lesions to the cerebellum can cause dyssynergia, dysmetria, dysdiadochokinesia, dysarthria and ataxia of stance and gait. Deficits are observed with movements on the same side of the body as the lesion (ipsilateral). Clinicians often use visual observation of people performing motor tasks in order to look for signs of ataxia.

Steppage gait (High stepping, Neuropathic gait) is a form of gait abnormality characterised by foot drop due to loss of dorsiflexion. The foot hangs with the toes pointing down, causing the toes to scrape the ground while walking, requiring someone to lift the leg higher than normal when walking.

It can be caused by damage to the deep peroneal nerve.

The initial symptoms in two-thirds of cases are loss of balance, lunging forward when mobilizing, fast walking, bumping into objects or people, and falls.

Other common early symptoms are changes in personality, general slowing of movement, and visual symptoms.

Later symptoms and signs are dementia (typically including loss of inhibition and ability to organize information), slurring of speech, difficulty swallowing, and difficulty moving the eyes, particularly in the vertical direction. The latter accounts for some of the falls experienced by these patients as they are unable to look up or down.

Some of the other signs are poor eyelid function, contracture of the facial muscles, a backward tilt of the head with stiffening of the , sleep disruption, urinary incontinence and constipation.

The visual symptoms are of particular importance in the diagnosis of this disorder. Patients typically complain of difficulty reading due to the inability to look down well. Notably, the ophthalmoparesis experienced by these patients mainly concerns voluntary eye movement and the inability to make vertical saccades, which is often worse with downward saccades. Patients tend to have difficulty looking down (a downgaze ) followed by the addition of an upgaze palsy. This vertical gaze paresis will correct when the examiner passively rolls the patient's head up and down as part of a test for the oculocephalic reflex. Involuntary eye movement, as elicited by Bell's phenomenon, for instance, may be closer to normal. On close inspection, eye movements called "square-wave jerks" may be visible when the patient fixes at distance. These are fine movements, that can be mistaken for nystagmus, except that they are saccadic in nature, with no smooth phase. Difficulties with convergence (convergence insufficiency), where the eyes come closer together while focusing on something near, like the pages of a book, is typical. Because the eyes have trouble coming together to focus at short distances, the patient may complain of diplopia (double vision) when reading.

Cardinal manifestations:

- Supranuclear ophthalmoplegia

- Neck dystonia

- Parkinsonism

- Pseudobulbar palsy

- Behavioral and cognitive impairment

- Imbalance and walking difficulty

- Frequent falls

Damage to the cerebellum, particularly to the cerebrocerebellum area and the cerebellar vermis, is very often associated with clinical depression and often with alcoholism. Due to difficulties in mobility, self-care, everyday activities, and pain/discomfort, those with cerebellar ataxia are more likely to be diagnosed with anxiety and depression. Almost a third of patients with isolated, late onset cerebellar ataxia go on to develop multiple system atrophy.

In recent years the cerebellum's role has been observed as not purely motor. It is intimately combined with intellect, emotion and planning.

Foot drop is characterized by steppage gait. While walking, people suffering the condition drag their toes along the ground or bend their knees to lift their foot higher than usual to avoid the dragging. This serves to raise the foot high enough to prevent the toe from dragging and prevents the slapping. To accommodate the toe drop, the patient may use a characteristic tiptoe walk on the opposite leg, raising the thigh excessively, as if walking upstairs, while letting the toe drop. Other gaits such as a wide outward leg swing (to avoid lifting the thigh excessively or to turn corners in the opposite direction of the affected limb) may also indicate foot drop.

Patients with painful disorders of sensation (dysesthesia) of the soles of the feet may have a similar gait but do not have foot drop. Because of the extreme pain evoked by even the slightest pressure on the feet, the patient walks as if walking barefoot on hot sand.

Symptoms typically begin sometime between the ages of 5 to 15 years, but in Late Onset FA may occur in the 20s or 30s. Symptoms include any combination, but not necessarily all, of the following:

- Muscle weakness in the arms and legs

- Loss of coordination

- Vision impairment

- Hearing impairment

- Slurred speech

- Curvature of the spine (scoliosis)

- High plantar arches (pes cavus deformity of the foot)

- Diabetes (about 20% of people with Friedreich's ataxia develop carbohydrate intolerance and 10% develop diabetes mellitus)

- Heart disorders (e.g., atrial fibrillation, and resultant tachycardia (fast heart rate) and hypertrophic cardiomyopathy)

It presents before 22 years of age with progressive staggering or stumbling gait and frequent falling. Lower extremities are more severely involved. The symptoms are slow and progressive. Long-term observation shows that many patients reach a plateau in symptoms in the patient's early adulthood. On average, after 10–15 years with the disease, patients are usually wheelchair bound and require assistance with all activities of daily living.

The following physical signs may be detected on physical examination:

- Cerebellar: nystagmus, fast saccadic eye movements, truncal ataxia, dysarthria, dysmetria.

- Lower motor neuron lesion: absent deep tendon reflexes.

- Pyramidal: extensor plantar responses, and distal weakness are commonly found.

- Dorsal column: Loss of vibratory and proprioceptive sensation occurs.

- Cardiac involvement occurs in 91% of patients, including cardiomegaly (up to dilated cardiomyopathy), symmetrical hypertrophy, heart murmurs, and conduction defects. Median age of death is 35 years, while females have better prognosis with a 20-year survival of 100% as compared to 63% in men.

20% of cases are found in association with diabetes mellitus.