Neuroscience
Vrije Universiteit Amsterdam
MOVE Research Institute Amsterdam
First Research Project - 26 EC 01-02-2016 to 06-10-2016
Age-differences in Quantification and
Consistency (over Tests) of Over- and
Underestimation of Physical Performances
Author: Antonia Kaiser 11118040 Co-assessor: Machiel Keestra Supervisor 1: Nick Kluft Supervisor 2: Mirjam Pijnappels Supervisor 3: Sjoerd Bruijn October 6, 2016
Performances
Antonia Kaiser
Abstract
Misjudgement of physical performance can lead to falls, especially in older adults. The pur-pose of this study was to find out if the misjudgement of physical performance is consistent over different tests. Four different physical tests were conducted in 7 older and 9 young participants. Participants first judged their performance and then actually executed the physical activity tests. Judgement was compared to performance to get the misjudgement. A negative misjudgement suggests underestimation and a positive misjudgement suggests overestimation. Statistical analysis revealed an average small negative misjudgement for all tests (underestimation), in average participants were very accurate in judging their per-formances. Misjudgement did not correlate between the different physical activity tests, suggesting that over- or underestimation is not consistent between tests. Judgement and performance individually were correlated between tests, which indicates that there is a con-sistency in judgement of physical performances between tests. This study gives hints for future research and provides a first insight in consistency of the quantification of over- and underestimation of physical performance.
Introduction
Falling is the 6th leading cause of death in older adults. Yearly, 30-50 percent of the adults over 65 years old experience a fall (Powell & Myers, 1995a). This is a major concern in health care, as falls are connected to fractures and other injuries in older adults (Stevens, Corso, Finkelstein, & Miller, 2006).
There are several factors that can lead to a fall. The Effective Health Care Bulletin (1996) states that there are over 400 potential risk factors. While there is no agreement about classification, we can divide risk factors into approximately five categories. Environmen-tal causes (e.g. lighting, unsafe situations or unfitting shoes), medication (e.g. hypnotics, antidepressants), medical conditions and changes associated with aging (e.g. changes in vision, cognitive changes, body changes), nutrition (e.g. calcium, vitamin D deficits) and lack of exercise (Masud & Morris, 2001). Nickens (1985) argues that environmental causes decrease in importance as age increases, whereas intrinsic causes become more important. One intrinsic cause is the ability in holding and shifting body-weight. In other words, keep-ing stability when workkeep-ing against the center of gravity (eg. standkeep-ing, walkkeep-ing). It is crucial for movements in everyday life and various functional tests (Kamata et al., 2007). Because keeping balance after a perturbation has been shown to be highly correlated with falls, we want to focus on this factor (Thorbahn & Newton, 1996). Keeping balance is a complex procedure. It is the ability to hold the center of mass within the basis of support, even with the threats of internal and external disturbances (Horak, 2006). Not only physical abilities are important for this process, also cognitive processes play a role in keeping balance. Here, over- and underestimation comes into focus. Overestimation in this context means, that the judgement of the ability to perform in a test exceeds the actual performance. An over-estimation can lead to situations, which are beyond the person’s abilities. Underover-estimation can be seen as the opposite. The actual performance exceeds the estimate of performance. Robinovitch and colleagues (Robinovitch, 1998) suggest that an underestimation means that the participant is cautious, because of fear of losing balance in the actual performance. The mismatch between actual performance and the judgement of the ability to perform is tied to falls. Delbaere and colleagues (Delbaere, Close, Mikolaizak, et al., 2010) showed, that older adults, that over- or underestimate their chance of falling, are more likely to fall. However not only the chance of falling can be over- or underestimated by older adults. For example Sakurai et al. (2013) showed that older adults overestimate their performance to step over a bar. Butler et al. (2015) found that some older adults over- or underestimated their performance to cross a plank. Finally, over- or underestimation of ability to perform was found to be correlated with falls (Sakurai et al., 2013; Butler, Lord, Taylor, & Fitzpatrick, 2014). Fear of falling is associated with a lack of training and practice in everyday life and may result in a fall (Delbaere, Crombez, Vanderstraeten, Willems, & Cambier, 2004) and is therefore likely to associate with underestimation. Situations in which older adults misjudge their performance can be very diverse. For instance, older adults can misjudge their stability limits and balance recovery ability, their ability to lift their feet or arms, bent their knees or their flexibility.
In order to diminish the number of falls in older adults, it is important to find out more about over- or underestimation of performance in older adults. If the quantification of the misjudgement of performance is consistent over tests, meaning specific for each individual,
a personalized treatment could be developed. Additionally, it would make a classification in risk potential possible before falls happen. It is important to find out, if such a misjudge-ment is consistent over tests, to be sure that people can be categorized by this factor. We hypothesize that, if people have the tendency to over- or underestimate, the level of misjudgement would be consistent over different tests. We used four different tests to inves-tigate this. Firstly, a test, where participants have to step-over a horizontal bar. Secondly, a test where participants have to step-over a distance. Thirdly, a test where participants have to step-over a line and fourthly a test where participants have to recover from a forward fall. We hypothesize that in some older adults an overestimation arises, because the body representation is not adjusted to the new situation (the aged body). In other words, that they still have the representation of a younger body in mind. Therefore they assume to be able to do some movements and notice too late that they are not able to. Sakurai et al (2013) already showed a negative correlation between actual performance and age, whereas estimated ability was not correlated with age. Furthermore, we hypothesize that other older adults are naturally more cautious and underestimate themselves to prevent injuries. These misjudgements can both have different intensities and (combination of) origins, depending on personality traits (i.e. self-confidence), experiences (i.e. previous fall history) and activ-ity in everyday life (i.e. sportiness).
Therefore the questions we want to answer are: Can we quantify over- and underestimation for participants and is the type and level of misjudgement (over- or underestimation) con-sistent over different tests? Are there age-related differences in these factors? To answer these questions older and young adults judge their physical performance in estimating their maximum performance and actually performed their maximum in four different balance challenging tests. The difference between the judged maximum and the actual maximum will be considered the misjudgement (over- and underestimation). These results are com-pared with young participants, to find out if there are any age-related differences. Our hypothesis is that we will find over- and underestimation in different intensities consis-tent over tests in the older participants. We expect young participants to have a lower misjudgement, that is consistent over tests.
Methods Participants
7 older (5 female; age: M = 76, SD = 5.37) and 9 young (5 female; age: M = 24.5, SD = 1.42) participants were recruited in Amsterdam, the Netherlands. Three out of 7 older adults (two female) had to be excluded from the analysis of the ’Release’-test, because they did not complete the test, because of personal concerns. The study was approved by the local Human Ethics Committee. All participants gave written informed consent. Older participants were interviewed on the phone and screened with a list of criteria (see
Appendix). All older participants had a MMSE-score over 25. Participants that were
included were invited for an assessment at the department of human movement sciences at the Vrije Universiteit Amsterdam. The experiment consisted of four different physical tests, one questionnaire and a movement imagery test. Older participants additionally did three questionnaires and one physical ability test. Before the experiment the older adults were tested with the Mini Mental State Examination (MMSE). The testing was
only proceeded if the participant had a score of 25 or higher, to make sure that none of our participants had severe cognitive impairments. (M. Folstein, Robins, & Helzer, 1983) Additionally the physical performance of the older participants were accessed with balance tests from the QuickScreen Clinical Falls Risk Assessments (QS)(Tiedemann, 2006) To assess how concerned the older participants were to fall, we conducted the Fall Efficacy Scale International and Activities-Specific Balance Confidence Scale questionnaires (FES-I and ABC). (Kempen et al., 2007; Powell & Myers, 1995a) As a movement imagery test we used the Vividness of Movement Imagery Questionnaire-2questionnaire (VMIQ-2). (Roberts, Callow, Hardy, Markland, & Bringer, 2008)
Experiment
Participants were asked to wear provided tight sports-shorts. Before the actual experi-ment started, leg length, body height, weight, grip strength, knee extension force and inseam length (inner leg length) were measured. Every physical test consisted of two different parts. First participants had to judge their performance in the respective test. Afterwards, the physical tests were performed to find the maximum performance of participants. To prevent any harm to the participants, two experimenters were securing the participants in case they struggled to maintain balance and got in danger of a fall. If help was needed the trial was not considered for further analysis and therefore repeated.
In the first test of the physical tests (’Obstacle’) participants had to judge their perfor-mance and tried to step over an obstacle. The obstacle (see figure 1) consisted of two stands with a scale, adjustable brackets and an attachable bar. The bar was attached to the brackets by a magnet, which provided stability while the bar could fall off easily when participants hit the bar.
Figure 1 . The ’Obstacle’-test set-up.
overstep without bumping the bar down. Doing so, they stood three meters away from the obstacle and were instructed to imagine themselves walking to the obstacle and overstep it without making a jump. We defined a jump as any situation where no foot touched the floor. The volunteers judged the maximum height four times. Twice, the experimenter moved the bar from up to down and twice from down to up. The subject said ’Stop’ to stop the bar on the deliberate height. If the participant felt the bar was not in the exact correct position an adjustment was allowed. For the actual performance measurement this proce-dure was repeated. Participants stood three meters in front of the obstacle and were asked to walk to the obstacle to step over the bar with a height of 15 cm for older participants and 30 cm for young participants. The bar was moved up in 5 cm steps until the participant failed two times to overstep that certain height. The bar was then lowered in small steps (1 cm) until the participant was able to overstep it again. This height was considered the maximum performance.
After this procedure, the participants were asked to stand at the three-meter distance mark again, to judge their inseam length. They indicated their judged height by stopping the experimenter again moving the bar once in a descending and once in an ascending order. In the second test (’River’) the maximum distance, participants thought and were actu-ally able to overstep, was assessed. Therefore, a lane or ’river’ was taped on the floor. The ’river’ was a 10 m long paper roll, which was 2 m wide on one side of the river and narrowed till it reached a width of 80 cm at the end of the ’river’. (figure 2)
Figure 2 . The ’River’-test set-up.
The participants were asked to start walking from a starting point, cross the ’river’ at a position they chose and return to an end position that they were instructed to arrive at as fast as possible. Participants were not allowed to run or jump and were instructed to arrive at the end point without ’wet feet’ (stepping into the ’river’). The starting and end point were taped at the widest end. The experimenter explicitly pointed out that going down the river makes it easier to overstep it, but will take more time. The distance which partici-pants chose to overstep and the time they needed was measured. The distance they chose to overstep was considered as an implicit measure of the judgement of their performance. This procedure was repeated four times, twice approaching the river from the left side and twice from the right side.
Afterwards the maximum step length of participants was tested. The experimenter placed a slip-proof mat next to a measuring scale on the floor and asked the participant to step on it (the heel had to be placed on the slip-proof mat). This procedure was repeated until
the volunteer failed. If that was the case, distance was decreased again, until the subject succeeded. This final distance determined the maximum step-length.
Figure 3 . The ’Line’-test set-up.
In the third test (’Line’) participants were asked to step over a stretched line between two stands (10 m long, 1.30 m/2 cm height; figure 3). This test was similar to the ’River’-test. A start and an end point were marked 3 m from the highest point of the line. The volunteers were asked to reach the end point as efficiently as possible, without running or jumping. The trade-off was again clearly explained. The procedure was repeated 4 times. The chosen height was measured as well as the time needed to return to the end position. The height that participants chose to overstep was considered as an implicit measure of the judgement of their maximal over-stepping performance.
This measurement was compared to the maximum over-stepping performance from the first test (’Obstacle’).
In the fourth test (’Release’) participants were secured with a harness, attached by a cable to the ceiling. The length of the rope was adjusted so that participants could not touch the ground with their knees. Another cable was attached to the harness and the wall behind the participant. This cable enabled participants to lean forward into a certain angle. The cable was fixed to the wall with a magnetic system, which could be released with a button-press. (figure 4)
The cable attached to the ceiling as well as the one attached to the wall were equipped with a force measuring device, to distinguish a fall from a non-fall. Participants wore Xsense sensors on their feet and on their back.
To bring participants in the right angle, a model was used. Therefore, the feet-position when
the participant was in 90◦to the ground was measured. Then the rope, that was attached
the wall behind the participant, was adjusted so that it had 90◦to the participant and wall.
The height of the rope to the ground and the distance of the heel of the participant to the wall were then used to calculate the respective feet-positions for all other angles. To guarantee that participants would not slip, slip-proof mats were used.
Figure 4 . The ’Release’-test set-up.
First, participants were brought into angles and asked if they could imagine themselves recovering from a fall given that leaning position. Recovering successfully was defined as a regain of balance using only one step, without support from the harness they wore. Every
participant started in an angle of 85◦, which was decreased by 5◦every round, until the
participant did not believe that he/she could still recover from it. It was then increased
in 2◦steps again, until they believed they could recover from it. This angle was defined as
their perceived maximum.
Secondly participants were brought into the same angles as before (starting at 85◦,
decreas-ing in 5◦steps). This time the rope was released from the wall and participants had to try
to recover from the fall. If they could not recover from a fall under a certain angle, and thus
were caught by the harness, the angle was again increased in 2◦steps to find the angle the
participant could still recover from. This angle was considered as the maximum recovery performance.
Statistics
Custom scripts in MATLAB R2015 were used to analyze the collected data. Partici-pants were divided in two age groups, namely the older adults (M = 76, SD = 5.37) and younger adults (M = 24.5, SD = 1.42). Repeated measures of experiments were averaged for each participant. Misjudgement was considered the difference between the judgement measurement and the performance measurement. In the ’Release’-test a fall was consid-ered a fall if the force-measurement showed a harness-support of more than 20 kg. This measurement was consistent with the observed fall-occurrence. The statistical analysis was divided into three parts. Firstly the judgement, secondly the performance and thirdly the misjudgement (the difference between judgement and performance) for every test was an-alyzed. Age-differences between judgements, performances and misjudgements were tested with a t-test. To find out if judgement, performance and misjudgement were consistent over tests a linear regression model was used. The consistency of judgement and performance is important to analyze, to see if our tests measured the same. Statistical significance was set to p<0.05.
Results General statistics
General descriptives and actual performance of both age groups are presented in table 1. Older participants had a mean FES-I score of 20.86, a mean ABC-score of 80.52 and a mean QS-score of 1.3. Older adults finished the TMT-A in average in 35.67 seconds, young participants needed 20.58 seconds. TMT-B was accomplished in 85.98 seconds by the older participants and in 42.96 seconds by the young participants. The mean scores for the VMIQ-2 were 21.89 (young) and 24.5 (old) for the external visual imagery; 20.78 (young) and 18.71 (old) for the internal visual imagery and 19.89 (young) and 25.64 (old) for the kinaesthetic imagery.
Age-differences were significant for the VMIQ-2 external(t(1) = 17.77, p = 0.04) and kineas-thetic (t(1) = 19.14, p = 0.03).
Judgement
Significant age-differences in judgement of all tests could only be found for the ’Release’-test (t(1) = 26.44, p = 0.02), older participants judged their maximum performance sig-nificantly smaller (here meaning a bigger angle) than young participants (old: M = 75.14, STD = 5.39; young: M = 69.67, STD = 4.72)(see figure 2).
To find out if the judgement of performance was consistent over tests, the judgements of the performances of all tests were compared with each other. All four tests were significantly correlated with each other (see figure 5). .
Figure 5 . Comparison of the judgements of performances of all tests with each other.(from
upper left to bottom right: p<0.001, R2=0.62; p<0.001, R2=0.6; p=0.002, R2=0.47;
Table 1 descriptive statistics
Measure Age-group Mean STD T-test
young 68.94 kg 12.95 Weight old 72.14 kg 15.17 t(15) = 20.73, p <0.001 young 171.22 cm 9.41 Height old 168.43 cm 9.47 t(15) = 73.70, p <0.001 young 90.33 cm 4.62 Leg-Length old 92.64 cm 6.07 t(15) = 69.69, p <0.001 young 82.5 cm 5.94 Inseam-Length old 78.46 cm 7.17 t(15) = 48.87, p <0.001 Grip-Strength young 24.50 kg (l) 24.29 kg (r) 11.63 (l) 13.66 (r) old 33.07 kg (l) 30.39 kg (r) 9.03 (l) 7.98 (r) t(15) = 10.53, p <0.001 (l) t(15) = 9.55, p <0.001 (r) Knee-Extension-Force young 20.21 kg (l) 22.37 kg (r) 10.00 (l) 8.52 (r) old 28.99 kg (l) 29.01 kg (r) 2.80 (l) 5.10 (r) t(14) = 11.21, p <0.001 (l) t(14) = 13.04, p <0.001 (r) FES-I old 20.86 6.54 ABC old 80.52 18.33 QS old 1.3 0.37 TMT-A TMT-B
young 20.58 sec (A)
42.96 sec (B)
3.73 (A) 19.50 (B)
old 35.67 sec (A)
85.98 sec (B) 5.71 (A) 41.67 (B) t(15) = 12.14, p <0.001 (A) t(15) = 6.64, p <0.001 (B) VMIQ-2 external internal kineasthetic young 21.89 (ex) 20.78 (int) 19.89 (kin) 10.66 (ex) 9.83 (int) 10.48 (kin) old 24.50 (ex) 18.71 (int) 25.64 (kin) 13.33 (ex) 10.19 (int) 11.76 (kin) t(15) = 7.97, p <0.001 (ex) t(15) = 8.19, p <0.001 (int) t(15) = 8.09, p <0.001 (kin)
Table 2
Age-differences for judgement of all tests
Test Age-group Mean STD T-test
young 71.39 4.82 Obstacle old 53.62 17.24 t(1) = 7.04, p = 0.09 young 116.83 14.31 River old 82.29 19.19 t(1) = 5.76, p = 0.11 young 72.72 11.72 Line old 49.45 13.19 t(1) = 5.25, p = 0.12 young 69.66 4.71 Release old 75.14 5.39 t(1) = 26.44, p = 0.02 Table 3
Age-differences for performances of all tests
Measure Age-group Mean STD T-test
young 79.33 cm 7.16 Obstacle old 62.43 cm 15.30 t(1) = 8.39, p =0.08 young 125.33 cm 17.66 River old 80.00 cm 21.97 t(1) = 4.53, p = 0.14 young 79.33 cm 7.15 Line old 62.43 cm 15.31 t(1) = 8.39, p = 0.08 young 62.00Âř 6.22 Release old 72.25Âř 5.56 t(1) = 13.10, p = 0.04 Performance
Significant differences in performance between age groups could only be found for the ’Release’-test (t(1) = 13.09, p = 0.04). Older participants were able to recover from a signif-icantly bigger angle (lower performance) (M = 72.25, STD = 5.56) than young participants (M = 62 , STD = 6.22) (see table 3).
Some body-measures were found to be significantly correlated to performance. The
’Obstacle’-test performance was significantly correlated to leg length (p = 0.04, R2 = 0.79)
and the left grip strength (p = 0.03, R2= 0.74). The ’River’-test performance had significant
correlations with the leg length (p < 0.001, R2 = 0.90) and the right grip strength (p <
0.001, R2= 0.89). Body-measures correlated to the ’Release’-test performance could not be
found. The performances of all tests were compared with each other to find out, if they were consistent over tests. The ’Obstacle’-test performance was significantly correlated with the
’River’-test performance (p < 0.001, R2 = 0.79), the ’Obstacle’-test performance was also
significantly correlated with the ’Release’-test performance (p < 0.01, R2 = 0.57) and the
’River’-test performance was significantly correlated with the ’Release’-test performance (p
Figure 6 . Correlations between performances of all tests.
Figure 7 . Misjudgement per test. The comparison between judgement and performance is shown. The diagonal line represents zero misjudgement, meaning that judgement and performance were exactly the same. Data points above this line represent over-estimation,
data-points under this line represent under-estimation. The axes of test ’Release’ are the other way around, because a smaller angle was considered ’better’, whereas in all other
Table 4
95% Confidence-Intervals for Intercept and Slope of all tests. Performance against Judgement
test 95% CI Intercept 95% CI Slope Obstacle [-23.4, 20.3] [0.61, 1.2]*
River [4.43, 47.17] [0.52, 0.91]*
Line [-37.13, 2.65] [0.84, 1.38]*
Release [-51.92, 95.23] [-0.43, 1.66]
Misjudgement
The judgement of participants was compared with the actual performance to find out
how good participants were in judging their performance. (see figure 7). On average,
judgements of performance of the ’Obstacle’-, ’Line’- and ’River’-test were similar to the actual performances, participants were not as good in judging their performance for the ’Release’-test. (see table 4). The misjudgement per participant of each test was calculated and investigated. Linear relations (see table 4) between the performance and the judgement were only found for the ’Obstacle’-, ’River’- and ’Line’-test. In all tests the mean misjudge-ment was negative, meaning a slight underestimation on average (Obstacle: M = -8.32, STD = 7.41; Inseam: M = -5.70, STD = 7.49; River: M = -3.78, STD = 13.23; Line: M = -9.39, STD = 6.81; Angle: M = -5.23 STD = 7.28). There were no significant differences between age-groups found. (see table 5)
Table 5
Age-differences for misjudgement of all tests
Measure Age-group Mean STD T-test
young -7.94 7.11 Obstacle old -8.80 8.32 t(1) = -19.49, p = 0.33 young -8.50 13.31 River old 2.29 11.18 t(1) = -0.58, p = 0.67 young -6.61 7.01 Line old -12.98 4.87 t(1) = -3.08, p = 0.20 young -7.67 7.5 Release old 0.25 2.06 t(1) = 5.60, p = 0.52
None of the misjudgements was correlated to any of the questionnaires. No significant correlations could be found between misjudgements of all tests. (see table 6 and figure 8).
tests Obstacle River Line Release
Obstacle
River
Line
Release
Figure 8 . Misjudgement of all tests compared between all tests. Table 6
Misjudgement of all tests compared between all tests.
tests Obstacle River Line Release
Obstacle p = 0.95, R2= -0.07 p = 0.79, R2 = -0.07 p = 0.41, R2 = -0.02 River p = 0.14, R2 = 0.09 p = 0.16, R2 = 0.01 Line p = 0.82, R2 = -0.08 Release Discussion Judgement
Both older and young participants were very accurate in their judgement of perfor-mances. The judgements of both age-groups only differed significantly in the ’Release’-test. Additionally, this test did not have a linear relationship between judgement and perfor-mance. These results indicate that the ’Release’-test might have been too hard to judge. One possible explanation could be the high risk-level, that participants had to cope with. This test was the only one in the experiment, that had perceived serious consequences in case of failure. This assumption can be supported by the termination of 3 older participants in this test. O’Brien and colleagues (2013) also showed in a previous study, that higher risk in a test leads to more underestimation of participants. The combination of too much risk
and an excessive difficulty could have lead to a arbitrary judgement of performance. More-over, we found significant age-differences for this test, indicating that young participants had less problems with the risk level of this test.
The judgement of three of the tests used in this study was very accurate. This could mean, that our participants were all very experienced in judging their physical performance, or that the ’Obstacle’-, ’River’- and ’Line’-test were very easy to judge.
All judgements of the tests were significantly correlated with each other. This means that participants that judged their performance high in one test also judged themselves high in another test, indicating a consistence in judgement over tests. The consistence of judge-ments over tests confirmed that all four tests measure judgement accurately. Furthermore, it shows that participants had a strategy in judging their performance, which stayed con-sistent over different tests. Older and young participants judged themselves the same way over tests. One explanation could be, that because of everyday life experience, participants evolve a certain strategy to judge their performances. This strategy is then used for all situations, where a pre-judgement is needed.
Performance
The ’Release’-test was the only one found to have a significant age-difference in per-formance. That indicates, that it was the only test, that challenged older participants differently than young ones. It points into the direction, that this test was too hard. This is in line with 3 older participants abandoning this test before completion.
All performances of all tests were found to be significantly correlated with each other. That means, that participants that performed better or worse in one test also performed better or worse in another test. This results confirmed that all our tests measure performance accurately and consistently.
Misjudgement
On average, all tests were slightly underestimated in both young and older adults, in fact the misjudgement was very small. This result indicates, that the difficulty level and risk of the ’Obstacle’-, ’River’- and ’Line’-test were very low. Another reason could be, that only adults participated in this study, that were very good in judging their performance. Additionally it could mean, that all participants were very fit. This assumption is also in line with the linear relation of judgement and performance in the ’Obstacle’-, ’River’- and ’Line’-test.
Age differences for misjudgement could not be found in any of the tests.
Correlations between the misjudgements of all tests did not show any significant results. Participants were therefore not consistent in their misjudgements over tests.
Over all, performance and judgement analyzed individually were consistent over tests, but the misjudgement (the difference between those two) was not. This indicates that partici-pants used a certain strategy to judge their performances and were also consistent in their physical performance, but did not consistently over- or underestimate themselves. One
possible explanation for this could be the general low misjudgement of our participants. The misjudgement of physical performance was overall very small and indicates very fit participants and easy tests.
Future Research
This study had some limitations. We could not find consistency of misjudgement over different tests, which could be explained by low statistical power because we only measured 9 young and 7 older adults.
Future studies about the quantification of over- and underestimation should take the fear influence into account. Influencing how frightening or precarious a test is, could reveal the type and quantification of the estimation in participants. Furthermore, it could help to use every-day movements and tests (e.g. climbing stairs). Participants would have more knowledge and practice in these types of tests. Additionally the risk of tests should be much higher than in our tests. A higher risk could reveal a clear distinction between over and underestimation, that is consistent over tests. Risk and difficulty should additionally be controlled over different tests.
Conclusion
Over all, this study has shown, that over- and underestimation of physical abilities was quantifiable, that judgement and performance alone were indeed consistent over tests, but misjudgement not. More research has to be done to investigate this question further.
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version1 – feb 2013
Checklist in-exclusion criteria older participants
for participation in experimental studies on standing or walking with moderate intensity
Instructions: This list needs to be checked on all older adults (> 65 years) participating in an
experimental study at the Faculty of Human Movement Sciences. explicit exclusion criteria:
o to be indicated in bold by the researchers o lead to immediate exclusion if the answer is YES o age and mental health always in bold other criteria:
o based on subsequent questions of these aspects, the principal investigator decides to exclude if the safety of participants cannot be warranted
Research title Self-Judgment of walking ability in older adults
Participant’s name Date of birth
Researcher’s name Nick Kluft, Antonia Kaiser Date
Age = No Yes
Are you under 65 years of age?
Are you older than 85years of age?
Mental health: MMSE score = No Yes
Mini Mental State Examination (MMSE) < 25 (max 30)
Mini Mental State Examination (MMSE) < 19
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MMSE test (Dutch version) available at ECB website;
>24: mentally healthy; 19-24: mild cognitive impairments; <19: severe cognitive impairment: exclusion
Anthropometry No Yes
Is your Body Mass Index > 30 kg/m2 Height:
Weight:
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Cardiovascular problems No Yes If yes, how often and when?
Have you ever had a heart attack and/or a bypass surgery in the past 6 months?
Have you ever had chest pain after 30 minutes exercise or stress? Have you ever had a stroke or brain hemorrhage?
A Transient Ischemic Attack (TIA) does not exclude participant
Have you ever had a pulmonary embolism?
Do you have high blood pressure (systolic blood pressure> 140, diastolic pressure> 90) and/or do you use drugs for high blood pressure? Do you have high cholesterol (> 5.2) and/or do you use medication for high cholesterol?
Have you ever fainted the last 6 months?
Exclude if >1 time with possibly vestibular, neurological or cardiovascular cause Do you have shortness of breath
after 20 minutes walking? Do you have any other heart problems (eg, cardiac palpitations, souffle, or panting) for which you have visited a cardiologist in the past year (if so, which)?
Do you sometimes experiencing lightheadedness? (e.g. due to decreased blood supply to the brain)
Joint disorders No Yes If yes, where and since when? Do you suffer from osteoporosis
(porous bones) or osteo-arthritis (joint degeneration) in the lower limb?
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Do you suffer from rheumatoid arthritis (joint inflammation) in the lower limb?
Did you ever had a joint replacement (hip or knee prosthesis)?
Neurological disorders No Yes If yes, (where) and since when? Do you have Parkinson's disease?
Have you ever experienced tingling or numbness in your hands, feet or legs (eg diabetic neuropathy)? Do you have any other neurological symptoms for which you have visited a neurologist in the past year (if so, which)?
Only exclude if paralysis, muscle weakness or sensitivity problems in lower limbs
Vestibular disorders No Yes If yes, how often?
Are you sometimes dizzy? (vertigo or sensation of spinning)
Exclude if >1 per week and within last 6 months
Do you have any difficulty in walking straight or turning a corner?
Lower extremities injuries No Yes If yes, where and to what extend recovered?
Did you break your leg in the past year?
Exclude if < 6 months or not fully recovered yet Did you have your knee or ankle
ligaments torn in the past year?
Do you have any pain in knee and hip joints or lower limb muscles in the past week, due to injury?
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Mobility and fall risk No Yes Additional remarks:
Do you use a walking aid (if so, what and how often)? Is it a problem for you to walk 10 minutes continuously without resting and without walking aid? Have you fallen in the past year (if yes, how often)?
Did you fall > 2 times in the past year? Do you have any difficulty in maintain straight posture for 10 minutes?
Vision and hearing No Yes Additional remarks: Do you have problems in reading the
newspaper (if necessary, with glasses or magnifying glass)? Do you have problems in recognizing someone’s face at a distance of 4 meters (if necessary, with glasses)?
If yes, a visual acuity test will be conducted whether the participant should be excluded
Do you have problems in hearing my questions?
Medication No Yes Additional remarks:
Did you use sleeping pills over the last week?
Indicate no use of pills 48 hours before measurement
Did you use anti-depressants over the last week? cause tremor and muscle weakness
Did you use beta-blockers over the past week? cause fatigue and dizziness
Appendix Screening Document
