Balance and Mobility
The Clinical Assessment Of Mobility
During the clinical assessment of balance and mobility it is crucial to actually observe an individual's mobility, to watch him or her get up and walk. Mary Tinetti, a Yale geriatrician, demonstrated that a standard neurological examination—of power, reflexes, sensation, and tone— less effectively identified impaired balance and mobility when compared with examination of actual standing and walking performance.
The assessment of balance and mobility can be facilitated by use of the principle of hierarchy. Someone who can perform a difficult task, such as climbing stairs, can be assumed to be able to safely perform simple tasks, such as getting out of a chair. Of course, an individual's abilities do not always strictly follow the hierarchy, but the principle holds in most situations.
A typical assessment of balance and mobility starts with the person in bed. He or she is watched rolling over, sitting up, getting out of bed, walking, and sitting down in a chair—and sometimes also watched turning, standing still, standing still under more challenging conditions (with eyes closed, withstanding a nudge, reaching forward), and climbing stairs. Use of the usual walking aid is permitted. Using the principle of hierarchy, an individual who is known to be able to perform at a high level, for example, walking, is observed performing only more challenging tasks, such as climbing stairs, not simple tasks like rolling over in bed. Formal balance and mobility tests are sometimes used; these are described in the review by MacKnight and Rockwood (1995a).
The balance and mobility assessment has implications for a patient's treatment and care needs. Any deficits in balance or mobility will have an important impact on an older adult's daily life. All of the basic and instrumental activities of daily living depend, to some extent, on independence in balance and mobility. For example, a patient who cannot roll over in bed will need to be turned every few hours to prevent pressure sores; one who can transfer and walk, but not stand safely for any length of time, will need to have the home modified so that tasks such as cleaning oneself and cooking can be done seated. Physiotherapy, occupational therapy, and other interventions can be directed to specific deficits.
A number of common patterns of gait abnormalities are seen in older adults:
- Nonspecific gait abnormality of aging; also sometimes disparagingly called the senile gait. People who exhibit this gait have some features of parkinsonism, with flexion at the hip and knees, forward trunk flexion, decreased arm swing, narrow stance, tendency to shuffle, and decreased gait velocity. Many older adults exhibit some features of this gait.
- Deconditioned gait, which is caused by disuse. Patients with this gait have most of the features of the nonspecific gait abnormality of aging. They also have weak muscles, particularly hip flexors (the muscles used to bend the hip). Scissoring is often present during walking, with one foot straying into the path of the other, leading to decreased walking balance. Step length, path, and frequency are very irregular. The deconditioned gait may also be related to sarcopenia, a significant loss of muscle mass that may be associated with aging.
- Hemiplegic gait is caused by a stroke. A stroke leads to weakness and spasticity (increased tone, particularly when the muscles are stretched). The classic hemiplegic gait involves an arm flexed at the elbow and held close to the body, with the leg on the same side held in a straight, stiff position and moved forward in a circular pattern (circumduction). Depending on the severity and extent of the stroke, these arm and leg conditions may or may not be present to varying degrees.
- Antalgic, or painful, gait is the limping gait. In older adults it is often due to osteoarthritis of the knee or hip. Treatment involves using a walking aid to shift the body's weight off the affected limb, pain control, weight loss, exercise to strengthen surrounding muscle, and sometimes replacing the affected joint with an artificial one.
- Parkinsonian gait is most commonly caused by Parkinson's disease, although other conditions, such as late Alzheimer's disease or side effects of drugs such as antipsychotics, can sometimes cause this gait abnormality. It is characterized by a narrow stance with short shuffling steps, the body stooped forward with knees and hips bent slightly, and a tremor in both hands, which are held at the sides. It is often difficult for the patient to start walking and, once started, it is often difficult to stop. This is known as festination. Some patients need to run into a wall or other obstacle in order to stop.
- Gait apraxia is the inability to carry out the previously learned motor activity of walking, despite normal strength, sensation, and joints. These patients often have difficulty initiating gait, taking broad-based, irregular steps. Gait apraxia is often due to cerebrovascular disease in the deep white matter of the brain.
- Fear of falling, although not strictly a gait disorder, is experienced by many patients who have had an important fall or other fright, such as getting stuck in the bathtub. They develop a significant fear of falling that then limits their mobility (and can lead to deconditioning). These patients often stay close to furniture and walls, take short, tentative steps, and prefer to walk with the support of another.