Affiliations: North Grandview Avenue, Odessa, TX, USA | Millikin University, Decatur, IL, USA | X-RTS Software Products, Inc., Hopedale, IL, USA
Note: [] Address for correspondence: Larry Feeler, PT, 4407 North
Grandview Avenue, Odessa, TX 79762, USA. Tel.: +1 432 638 1754; E-mail: lfeeler@grandecom.net
Abstract: Objective: To determine if isometric (static) strength accurately
predicts dynamic lifting capacity. Participants: 107,755 male and 23,078 female prospective workers taking part in a post-offer employment test. Methods: Subjects were tested for strength three standard static lifts
and attained physical maxima for four dynamic lifts. Results: The data confirms modest correlations between isometric and dynamic measures. However,
the standard errors of estimate for all isometric-to-dynamic predictions make
such predictions meaningless for the practical purpose for which they are most
commonly used. Conclusions: The Static Leg Lift, Static Arm Lift and
Static Back (Torso) Lift are not appropriate for making predictions relative to
dynamic lifting capacity. Given the likely degree of error in such predictions,
and in light of potential safety concerns as reported by previous
investigators, employers, clinicians and risk managers now have substantial
objective evidence to call such testing into question.
Keywords: Employment testing, post-offer testing, strength testing, static leg lift, static arm lift static back lift
