Mobility impairment and off legs in adults

Gait abnormalities or unsteadiness are a common presenting complaint, especially in older patients. It may be a trivial complaint with no underlying pathology or herald a more serious illness.

The concept of 'off legs' usually refers to elderly patients, who were previously mobile and active, with a sudden deterioration. The cause of 'off legs' is usually an acute illness - eg, chest infection, urinary tract infection. 'Off legs' is a non-specific presentation, with a wide variety of causes. In emergency departments, it is a high-risk presentation, with a 30-day mortality rate of 6%.¹

Those who lose independent mobility are less likely to remain in the community, have higher rates of disease, have a poorer quality of life and a greater likelihood of social isolation.

This article is primarily focused on mobility impairment in adults.

How common is mobility impairment in adults? (Epidemiology)

• The most common risk factors for mobility impairment are older age, low physical activity, obesity, strength or balance impairment, and chronic diseases such as diabetes or arthritis.

• The prevalence of gait and balance disorders is around 10 % between the ages of 60 and 69 years and more than 60% in those over 80 years.²

• About 30% of people aged 65 years and over have a fall at least once each year, increasing to 50% in people aged 80 years and over.³

• In 2016-2017 there were around 210,553 falls-related emergency hospital admissions among people aged 65 years and over, with around 67% of these people aged 80 years and over.

Assessment

History

• Patients may complain directly of problems with walking or simply of unsteadiness.

• It is important to clarify exactly what the patient feels - eg, which aspect of walking is difficult.

• Ask about falls - establish when the last fall occurred, how frequent falls are and whether there are any syncope or presyncope symptoms. See the separate Prevention of Falls in the Elderly article for details.

• Also, determine duration of problems.

• A full review of systems is required, especially looking for cardiac or neurological disease.

• Ask specifically for features suggestive of cord compression - eg, urinary retention, sensory and/or motor loss.

• Take a full drug history, especially as the aetiology may relate to polypharmacy or drug side-effects.

Examination

• Pulse rate, rhythm, volume and presence or absence of carotid bruits.

• Blood pressure including postural hypotension.

• Cardiovascular examination looking particularly for murmurs - eg, aortic stenosis.

• Full neurological examination looking for pyramidal, extrapyramidal and cerebellar dysfunction, and testing sensation for signs of peripheral neuropathy. See also the separate Neurological Examination of the Lower Limbs article.

• Do not forget the possibility of fractures and injuries - look for leg asymmetry and test the spine and lower limbs for tenderness.

• Examine the gait - asymmetrical or symmetrical problems, presence of waddling gait, broad-based gait, scissoring gait (bilateral leg spasticity), or ataxia.

• Consider further testing:³

  • With the 'Timed Up & Go' test, you time the person getting up from a chair without using their arms, walking three metres, turning around, returning to the chair, and sitting down. If the person usually uses a walking aid, this can be used during the test.

  • A score of 12-15 seconds or more has been shown to indicate high risk of falls in older people.

  • Also consider the 'Turn 180°' test where you ask the person to stand up and step around until they are facing the opposite direction. If the person takes more than four steps, further assessment should be considered.

Mobility impairment causes and differential diagnosis

Causes of mobility impairment

Causes of difficulty in walking can be broad and the following table lists some of these:

Causes of 'off legs'

As mentioned above, 'off legs' usually present in elderly patients and can be interpreted in various ways. This ranges from unsteadiness and difficulty with walking to dizziness or lethargy. The exact meaning should be sought during the assessment of the patient.

The causes of 'off legs' are usually acute and some causes include:

• Urine or chest infections.

• Dehydration.

• Neurological causes - eg, head injury, cord compression/cauda equina syndrome.

• Orthopaedic causes - eg, fractures (consider especially in elderly patients with osteoporosis who can fracture their neck of femur without major trauma).

• Metabolic abnormalities - eg, hyponatraemia, hypercalcaemia, hypoglycaemia or hyperglycaemia.

• Alcohol, drug or medications, especially as there are risks of polypharmacy in elderly patients.

• Hypoxia.

Investigations

These should be guided by the history and examination and may include cerebral imaging (eg, CT or MRI scanning) and blood tests (eg, TFTs, syphilis serology, etc).

Mobility impairment treatment

This is directed towards the underlying cause. If the cause is multifactorial then a multidisciplinary approach may be appropriate - eg, physiotherapist, occupational therapists and allied healthcare professionals.

See the separate Prevention of Falls in the Elderly article.