Measuring Up to Expectation: Cognitive Bias in Wrist Range-of-Motion Measurement.

Study Design Controlled laboratory study, cross-sectional design. Background The role of cognitive biases and their effect on a wide range of aspects relevant to clinical medicine has become the focus of a growing body of research, yet their effect in physical therapy is not well established. Objectives To test whether anchoring information provided to physical therapists prior to assessment of wrist range of motion (ROM) may induce bias in the measurement. Methods A total of 120 physical therapists participated in the study. Participants were asked to measure passive wrist extension ROM of a 65-year-old woman with no history of injury to the upper limb using a universal goniometer. Before initiating the measurement, some participants received a clinical description, which included sham information about the patient's health history. Three groups were differentiated according to the provided clinical content: no bias (n = 38), moderate bias (n = 41), and substantial bias (n = 41). An analysis of covariance was applied to test for differences between the 3 groups while controlling for any potential sex and experience effects. Results The analysis of covariance yielded a significant group effect (P = .009), with no significant effect for sex and experience. The adjusted mean wrist ROM was 80.2° for the no-bias group, 74.5° for the moderate-bias group, and 72.4° for the substantial-bias group. Post hoc tests demonstrated significant difference only between the group with no bias and the substantial-bias group (mean difference, 7.7°; P = .009). Conclusion Anchoring information was associated with differential results of an objective test. Physical therapists should increase their awareness of biases and consider employing debiasing strategies. J Orthop Sports Phys Ther 2016;46(12):1037-1041. Epub 30 Oct 2016. doi:10.2519/jospt.2016.6845.

Effect of focus of attention on transfer of a postural control task following an ankle sprain.

STUDY DESIGN: Randomized clinical trial. OBJECTIVE: To examine the effect of attentional focus instructions during training on the transfer of a learned balance capability to a more challenging condition among subjects with ankle ligament injury. BACKGROUND: Current evidence suggests that instructions inducing an external focus of attention may be more effective at promoting learning than instructions inducing an internal focus of attention. The effect of attentional direction on transfer has not been tested in populations following a disease or injury, such as lateral ankle sprain, in which postural control is impaired. METHODS AND MEASURES: Participants were 36 male volunteers (mean age, 20.9 years; range, 19-33 years) who were referred to physical therapy following a grade 1 or 2 ankle sprain. The patients were randomly allocated to 1 of 2 groups, which were instructed to focus attention either internally or externally during postural control training. Three training sessions were conducted on consecutive days and consisted of ten 20-second trials at 2 stability levels, using the Biodex Stability System. Postural control at an untrained, less stable level was assessed before the initial training session and 48 hours following the last session using the Biodex Stability System. Three measures of stability were used: (1) overall stability, as indicated by the variance in platform displacement in all directions, (2) anterior/posterior variance of platform displacement, and (3) medial/lateral variance of platform displacement. RESULTS: Participants utilizing an external focus of attention improved significantly over the study period in all 3 stability indices, while those utilizing internal focus of attention did not improve significantly. CONCLUSIONS: Our results suggest that an external focus of attention is advantageous for the transfer of learning of a postural control task following an ankle injury. Furthermore, they indicate that using an external focus of attention when training under moderately unstable conditions can significantly improve postural control under less stable conditions.

Effect of attention focus on acquisition and retention of postural control following ankle sprain.

OBJECTIVE: To examine the effect of attentional focus instructions and dynamic balance training on ankle sprain recovery. DESIGN: Randomized controlled trial. SETTING: Outpatient physical therapy department. PARTICIPANTS: Forty volunteers (age range, 19-33y) referred to treatment within 4 months after sustaining a grade 1 or 2 ankle sprain with no concurrent impairments. Participants were randomly allocated to 1 of 2 groups differing in training instructions. INTERVENTION: Postural control training consisted of ten 20-second trials, performed on 3 consecutive days, at 2 stability levels of the Biodex Stability System (BSS). Training instructions directed the participants to either an internal or an external focus of attention. Assessments were conducted on the BSS pre- and post-training, and 48 hours after the last session (retention test). MAIN OUTCOME MEASURES: Overall stability as indicated by variance in platform displacement in all directions; anteroposterior (AP) variance of platform displacement; and mediolateral variance of platform displacement. RESULTS: Increases in overall and AP stability were observed immediately following training in both groups and were maintained at the retention test. Interaction effect indicates greater improvement in the external-focus group. CONCLUSIONS: Our results suggest that external focus of attention is advantageous for the learning of a postural control task following an ankle injury.