title: Semmes-weinstein monofilaments: influence of temperature, humidity, and age.
abstract: OBJECTIVE
  To determine whether the buckling force of Semmes-Weinstein monofilaments is influenced by changes in temperature, humidity, and aging.
  
  
  METHODS
  We tested 16 Semmes-Weinstein monofilaments from North Coast Medical, varying in age from new to 12 years old. From each kit, we used the 2.83/0.07 g, 3.61/0.4 g, 4.31/2g, and 4.56/4 g filaments. Four observers tested the filaments under temperature/humidity conditions of 26°C/33%, 26°C/80%, 37°C/33%, and 37°C/80%.
  
  
  RESULTS
  Air temperature and humidity both significantly influence buckling force. At 26°C/33% the buckling force varies by an average of 2% from the standard data supplied by the manufacturer, whereas in the other 3 conditions (26°C/80%, 37°C/33%, and 37°C/80%), the buckling force can decrease by as much as 39%. Effect of age was small and not clinically relevant.
  
  
  CONCLUSIONS
  The significant changes in buckling force of the Semmes-Weinstein monofilaments in different temperature and humidity conditions might lead to a potential misinterpretation by the examiner regarding the level of peripheral nerve function loss. This could lead to incorrect diagnosis and treatment.
  
  
  CONCLUSIONS
  Examiners should be aware when using Semmes-Weinstein monofilaments that the environmental effects of temperature and humidity can affect the accuracy of measurement.
authors.affiliation: VU Medical Center, Amsterdam, The Netherlands.
authors.forename: Max H
authors.initials: MH
authors.lastname: Haloua
authors.forename: Inger
authors.initials: I
authors.lastname: Sierevelt
authors.forename: Willem J
authors.initials: WJ
authors.lastname: Theuvenet
mesh_terms: D000367:Age Factors; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D009431:Neural Conduction; D015588:Observer Variation; D058748:Pain Perception / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis*; D010812:Physical Stimulation / Q000295:instrumentation*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds / Q000502:physiology*; D012867:Skin / Q000294:innervation*; D013696:Temperature