Muscle Spindles and Locomotor Control-An Unrecognized Falls Determinant?

Abstract

BACKGROUND: Historically, evidence muscle spindles might be involved in locomotion was provided by their presence in tetrapod antigravity muscles associated with posture and locomotion. Later, Brodal (1962) noted muscle spindles in all muscles of locomotion. To unravel the complexity of the muscle spindle and its role in human locomotor control many investigators have since conducted lesion and/or anaesthesia studies in subhuman species and human contexts. QUESTIONS: How strong is the evidence linking muscle spindles to normal human locomotion and its control? Can a case be made for an association between muscle spindle dysfunction and falls injuries? METHODS: All relevant publications in the leading electronic databases were searched using the key terms muscle afferents, falls, gait, locomotion, muscle spindles. There were numerous related listings, but here only selected reports are examined and discussed because the articles had to be linked in some way to the key question driving the research. RESULTS: Evidence supports a key role for muscle spindles in the control of human locomotion, and by analogy to falls related injuries. CONCLUSION: Future work to explore the role of muscle spindles in the context of falls that occur when walking is warranted.