Developing a multivariate prediction model of falls among older community-dwelling adults using measures of neuromuscular control and proprioceptive acuity: A pilot study.

OBJECTIVE: To examine whether measures of neuromuscular control and proprioceptive acuity were predictive of falls in an older community-dwelling population and to develop a multivariate prediction model. METHODS: Fifty-eight adults aged above 60 living independently in the community were recruited for a prospective falls study. On entry, they undertook a Sensory Organisation Test (SOT) and an Active Movement Extent Discrimination Assessment (AMEDA) and completed a short fall risk questionnaire. Participants were monitored for falls over the subsequent 12 months. Prior to analysis, falls were classified into three categories based on the difficulty of the activity being undertaken and the demands of the environment in which the fall occurred. Logistic regression was used to predict the probability of a fall. RESULTS: For falls occurring under the least challenging circumstances, the model fitted using the AMEDA score and two of the questions from the fall risk questionnaire, related to balance and confidence, achieved a specificity of 87% and sensitivity of 83%. Falls occurring in more challenging circumstances could not be predicted with any accuracy based on the variables recorded at inception. CONCLUSIONS: This study highlights the importance of considering the heterogeneous nature of falls. Poorer proprioceptive acuity appears to play a role in falls occurring where neither the environment nor the activity is challenging, but not in falls occurring in other circumstances. Falls in the least-challenging circumstances affected 15% of participants, but this group was considerably more likely to have multiple falls, increasing their vulnerability to adverse consequences.

Daily surveillance of falls is feasible and reveals a high incidence of falls among older adults.

OBJECTIVE: To ensure accurate data capture for a fall study through a system of daily contact with participants. METHODS: Fifty-eight adults older than 60 years of age and living independently in the community in Canberra, Australia, were recruited for a prospective fall study. We adopted a system of daily contact with study participants for at least 12 months, either by email or by text, asking whether they had suffered a fall in the previous 24 h. At the final testing session, we asked participants whether they had experienced a fall during the previous twelve months. RESULTS: We found no evidence that the daily reporting regime led to excess participant attrition. Only three participants withdrew over the course of the study, and the burden of responding was not cited as a factor in any of these cases. Of the 55 participants who completed the full twelve-month study period, 38 (69%) experienced at least one fall. We also identified inconsistencies between recall of falls occurring during the last twelve months of the study and the contemporaneously recorded data. CONCLUSIONS: Previous studies have found that increasing the reporting demands on fall study participants will lead to higher attrition. This study demonstrates that it is possible to maintain participant engagement and minimise attrition with appropriate design of reporting procedures. We confirm existing evidence regarding the unreliability of retrospective recall of falls. The study highlights the importance of comprehensive and accurate data capture and points to the possibility of under-reporting of fall incidence.

Chronic ankle instability affects learning rate during repeated proprioception testing.

OBJECTIVES: 1. To determine whether individuals with chronic ankle instability (CAI) have lower proprioception sensitivity scores from a test on the Active Movement Extent Discrimination Apparatus (AMEDA). 2. To determine whether individuals with CAI can improve proprioception sensitivity scores with repeated active movement testing using the AMEDA. 3. To assess the test-retest reliability of the AMEDA. DESIGN: A cohort study comparing those with CAI or healthy ankles. SETTING: University clinical laboratory. PARTICIPANTS: 61 healthy university students, 36 with CAI, 25 with stable ankles. MAIN OUTCOME MEASURES: A 2-way ANOVA was conducted to compare performance of CAI and stable ankle groups, over 3 test repetitions on the AMEDA. The reliability intra-class correlation coefficient (ICC) was obtained for test repetitions. RESULTS: The scores improved in both groups when the AMEDA test was repeated (p = <0.001). The rates of improvement in proprioception test scores differed, with the CAI group showing a slower learning rate than the stable ankle group (p = 0.047). The ICC for the whole group across the three trials was 0.80 (95% CI = 0.69 to 0.87, p = <0.001). CONCLUSIONS: CAI participants improve their proprioception scores more slowly upon repeated AMEDA testing, suggesting differences in learning strategies.

Functional performance deficits associated with ligamentous instability at the ankle.

OBJECTIVES: To examine whether ankle anterior drawer ligament laxity is associated with deficits in performance testing among otherwise healthy sportspeople. DESIGN: Cross-sectional cohort study. METHODS: Eighty-six volunteers from among sports participants at a military academy consented to the use of their pre-participation musculoskeletal screening information for the lower limb, and to an additional test of ankle proprioception. The lower limb screening included tests of ankle ligament laxity, dorsiflexion range of movement, single leg hop-for-distance, hexagon agility hopping test, and hop-and-hold landing stability test. RESULTS: There was a significant difference between lax and stable ankles on the 4 screening tests when they were examined together with MANOVA (F=3.52, df=4, 167, p=0.009, Wilks' Lambda=0.92). Independent t-tests showed worse performance on the hop-for-distance (p=0.001), hexagon hop (p=0.039) and the proprioception tests (p=0.033) associated with laxity. Comparing stable and unstable ankles in the same individual, paired t-tests showed significantly lower hop counts for lax ankles on the hexagon hop test (p=<0.001). CONCLUSIONS: Ankle ligament laxity is associated with persisting deficits in explosive power, agility and proprioception, as demonstrated by less hopping distance, fewer hops in hexagon hop testing, and reduced proprioceptive acuity, despite ongoing participation in sport. Attention to maximising sport-related performance in the late stages of rehabilitation is suggested as an essential addition to clinical management of these injuries.