Using the coefficient of variation to detect sincerity of effort of grip strength: a literature review.

Many clinicians use the coefficient of variation (CV) to assess sincerity of effort, without understanding the premise on which it is based or its physiological and mathematical bases. Clinicians who use computerized evaluation systems that calculate the CV may not even be aware of the formula used to derive it. The wide use of the CV in detecting sincerity of effort of grip strength is puzzling, since it lacks empirical support in the literature. This paper examines the physiological rationale for using measures of variability to detect sincerity of effort, the mathematical basis on which the CV is founded, and the reliability and validity of the CV. The conclusions based on this literature review are that the CV is not an appropriate method for determining whether an effort is sincere and that CV values may be inflated in injured patients with compromised hand strength.

[1]  V. Mathiowetz,et al.  Grip and pinch strength: normative data for adults. , 1985, Archives of physical medicine and rehabilitation.

[2]  F. Biering-Sørensen.  Physical measurements as risk indicators for low-back trouble over a one-year period. , 1984, Spine.

[3]  G. Lister,et al.  Detection of submaximal effort by use of the rapid exchange grip. , 1989, The Journal of hand surgery.

[4]  H M Stokes,et al.  The seriously uninjured hand--weakness of grip. , 1983, Journal of occupational medicine. : official publication of the Industrial Medical Association.

[5]  M E Robinson,et al.  Reproducibility of maximal versus submaximal efforts in an isometric lumbar extension task. , 1991, Journal of spinal disorders.

[6]  Richard L. Scheaffer,et al.  Statistics for engineers , 1982 .

[7]  Denis Brunt,et al.  Assessment in occupational therapy and physical therapy , 1997 .

[8]  J. Baker,et al.  Burden of proof in detection of submaximal effort. , 1998, Work.

[9]  G. Lister,et al.  Measurement of grip strength in the diagnosis of wrist pain. , 1988, The Journal of hand surgery.

[10]  B. Niebuhr,et al.  Voluntary Control of Submaximal Grip Strength , 1990, American journal of physical medicine & rehabilitation.

[11]  Simple method to determine sincerity of effort during a maximal isometric test of grip strength. , 1983 .

[12]  D H Janda,et al.  Objective evaluation of grip strength. , 1987, Journal of occupational medicine. : official publication of the Industrial Medical Association.

[13]  P M King.  Analysis of approaches to detection of sincerity of effort through grip strength measurement. , 1998, Work.

[14]  R B Stein,et al.  The orderly recruitment of human motor units during voluntary isometric contractions , 1973, The Journal of physiology.

[15]  H. M. Stokes,et al.  Identification of low-effort patients through dynamometry. , 1995, The Journal of hand surgery.

[16]  J C Simonsen.  Coefficient of variation as a measure of subject effort. , 1995, Archives of physical medicine and rehabilitation.

[17]  S. Mackinnon,et al.  An evaluation of rapid exchange and simultaneous grip tests. , 1993, The Journal of hand surgery.

[18]  S Carlsöö,et al.  With what degree of precision can voluntary static muscle force be repeated? , 2020, Scandinavian journal of rehabilitation medicine.

[19]  M. Pellowski,et al.  Fluctuation in grip and pinch strength among normal subjects. , 1989, The Journal of hand surgery.

[20]  John P. Wiedemer.  Real Estate Investment , 1979 .

[21]  P. Åstrand,et al.  Textbook of Work Physiology , 1970 .

[22]  D. Lechner,et al.  Detecting sincerity of effort: a summary of methods and approaches. , 1998, Physical therapy.

[23]  G. Lister.  The Hand: Diagnosis and Indications , 1984 .

[24]  E. Fess,et al.  The need for reliability and validity in hand assessment instruments. , 1986, The Journal of hand surgery.

[25]  Richard C. Nelson,et al.  Assessing Sincerity of Effort in Maximal Grip Strength Tests , 1989, American journal of physical medicine & rehabilitation.

[26]  B. Niebuhr,et al.  Detecting sincerity of effort when measuring grip strength. , 1987, American journal of physical medicine.

[27]  T Hansson,et al.  Isometric Strength Testing: Recommendations Based on a Statistical Analysis of the Procedure , 1986, Spine.

[28]  V. Edgerton,et al.  Mammalian Muscle Fiber Types and Their Adaptability , 1978 .

[29]  R. Ashford,et al.  Sensitivity of the Jamar Dynamometer in detecting submaximal grip effort. , 1996, The Journal of hand surgery.

[30]  K. Schultz-Johnson.  Assessment of upper extremity-injured persons' return to work potential. , 1987, The Journal of hand surgery.

[31]  H. C. Hoeck,et al.  Reproducibility of Growth Hormone and Cortisol Responses to the Insulin Tolerance Test and the Short ACTH Test in Normal Adults , 1997, Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme.

[32]  J. Katz,et al.  A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. , 1993, The Journal of bone and joint surgery. American volume.

[33]  R. Rogers,et al.  Changes in measured spirometric indices. What is significant? , 1981, Chest.

[34]  Electromyographic analysis of effort in grip strength assessment. , 1993, Electromyography and clinical neurophysiology.

[35]  M. Robinson,et al.  Detection of submaximal effort in isometric and isokinetic knee extension tests. , 1996, The Journal of orthopaedic and sports physical therapy.

[36]  C. Bechtol,et al.  Grip test; the use of a dynamometer with adjustable handle spacings. , 1954, The Journal of bone and joint surgery. American volume.

[37]  Orit Shechtman,et al.  Is the coefficient of variation a valid measure for detecting sincerity of effort of grip strength? , 1999, Work.

[38]  R. Stein,et al.  Changes in firing rate of human motor units during linearly changing voluntary contractions , 1973, The Journal of physiology.

[39]  P. Harber,et al.  Static ergonomic strength testing in evaluating occupational back pain. , 1984, Journal of occupational medicine. : official publication of the Industrial Medical Association.

[40]  H Krombholz.  On the Association of Effort and Force of Handgrip , 1985, Perceptual and motor skills.

[41]  V. Mathiowetz,et al.  Reliability and validity of grip and pinch strength evaluations. , 1984, The Journal of hand surgery.

[42]  Grip measurements as a part of the pre-placement evaluation , 1965 .

[43]  A L Dellon,et al.  Detection of submaximal effort with computer-assisted grip strength measurements. , 1997, Journal of occupational and environmental medicine.

[44]  R. de Marco,et al.  Long-term instability of fasting plasma glucose, a novel predictor of cardiovascular mortality in elderly patients with non-insulin-dependent diabetes mellitus: the Verona Diabetes Study. , 1997, Circulation.

[45]  R W Bohannon,et al.  DIFFERENTIATION OF MAXIMAL FROM SUBMAXIMAL STATIC ELBOW FLEXOR EFFORTS BY MEASUREMENT VARIABILITY , 1987, American journal of physical medicine.