Introduction

Falls are frequent in the elderly, often leading to significant injury, transfer to residential care or death. Well-recognised risk factors include medications (particularly polypharmacy and the use of psychotropic agents), cognitive impairment, pre-existing gait disturbance, age-related muscular wasting (sarcopenia), dizziness and syncope (box 1). However, the cause of many falls, described by WB Matthews1 as ‘The Undiagnosable Blackout’, remains unexplained. When the fall is sudden and not associated with a perceptible loss of consciousness, it has been described as a drop attack.2

To our knowledge, this term was introduced by Sheldon2 in 1960, in describing elderly patients who fell, often with preservation of consciousness, but who were unable to rise for minutes, or sometimes hours. Greenwood and Hopkins3 later commented that some, although remaining conscious, appeared unable to generate sufficient antigravity muscle tension in time to prevent falling. A correlation between postural instability and the tendency to trip with age, found by Overstall et al,4 did not explain these patients’ inability to avoid a fall.

Sheldon2 had commented that older people frequently reported inability, after tripping, to preserve their balance—saying ‘once you’re going, you’ve got to go’. This remark reveals a pre-existing age-related problem with balance. He noted ‘they appear to fall under the unrestrained pull of gravity and the speed of descent is such that injuries are common…there is little doubt that the loss of power is associated with a loss of muscle tone – a flaccid state’. …