Sports Medicine Research: In the Lab & In the Field: (Hop) Around. (Hop) Around. (Hop) up (Hop) up and Get Down (Sports Med Res)
Friday, May 18, 2012

(Hop) Around. (Hop) Around. (Hop) up (Hop) up and Get Down

The multiple hop test: a discriminative or evaluative instrument for chronic ankle instability?

Eechaute C, Bautmans I, De Hertogh W, Vaes P. Clin J Sport Med. 2012 May;22(3):228-33. http://www.ncbi.nlm.nih.gov/pubmed/22504375

Chronic ankle instability (CAI) is a common concern for patients with a history of ankle sprains but can be very challenging to diagnose.  Previous studies have validated the multiple-hop test for assessing functional deficits as well as dynamic postural stability among participants with CAI.  However, before this test can be applied in the clinical setting it is important to determine if it can accurately diagnose patients with CAI and if it is sensitive to change over time. Therefore, the purpose of this study was to determine if the multiple hop test is an evaluative (if it could measure change over time) or discriminative (if it can differentiate patients with and without CAI; 29 participants/group) test for CAI. Inclusion criteria for the patients with CAI were: 1) history of lateral ankle sprain requiring 2 or more medical consults, 2) complaints of repetitive lateral ankle sprains for more than 6 months, 3) presence/fear of the ankle “giving way”, and 4) reporting a decreased level of ankle performance in recreational, competitive, or professional sports/activities. To complete the multiple hop test the participants were instructed to hop from and land on one leg through each 11 numbered points. The participants were instructed to maintain their balance and avoid posture correction (balance errors). After landing, the participants were told to stand still and then to resume the single-leg, hands-on hips, start position and then finally hop to the next point. Both legs were tested in a random order with a practice trial for each leg. The participants performed 3 reps on each leg with 3 minutes between reps (30 sec between legs). The participants were scored on 3 outcomes: 1) the total number of balance errors across three trials (range 0 to 30), as assessed on video tape, 2) the average time taken to complete the test, and 3) the participant-reported perceived difficulty measured on a 100-mm visual analog scale ranging from 0 = “not difficult”  to 100 = “impossible to perform.” The authors found that the multiple-hop test was deemed to be an effective discriminative test for differentiating participants with and without CAI, based on participants with CAI having poorer performance. For the three outcomes, the authors determined the optimal cut-offs for differentiating those with and without CAI: 1) 13.5 errors, 2) 35 seconds to complete the test, and 3) 32.5 mm on the visual analog scale for perceived difficulty. The authors found that when two of the outcomes were positive (based on the cutoffs above) the multiple hop test had the best ability to differentiate those with and without CAI (diagnostic accuracy ~ 83%, sensitivity ~ 86%, specificity ~ 79%) .While the multiple hop test may be able to discriminate the authors found that the test’s ability to detect a change may be limited. They calculated that the minimal detectable change for each outcome was quite large (the minimal detectable change was based on how much the test varies among the participants and how the outcomes vary over several trials). To detect changes participants would need to increase or decrease their outcomes by ~ 7 errors, 2) 6 seconds to complete the test, and 3) 27 to 55 mm on the visual analog scale for perceived difficulty.

This is an important study because it demonstrates that the multiple-hop test may be capable of discriminating patients with and without CAI but not as effective at monitoring change over time.  It is important to note that the authors  state that they are not certain which combination of outcomes best illustrates the presence of CAI. The authors state there are some flaws in the make-up in this study, and as it stands, more studies are going to need to be done to find which outcomes help to determine the multiple-hop test's evaluative and discriminative properties. For example, there are several other approaches to assess the ability of the multiple-hop test to detect change over time. What are your thoughts on the use of the multiple-hop test for assessing ankle function? Are you using anything like it in your setting to assess CAI?

Written by: Mark Rice
Reviewed by: Steve Thomas and Jeffrey Driban

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Eechaute C, Bautmans I, De Hertogh W, & Vaes P (2012). The multiple hop test: a discriminative or evaluative instrument for chronic ankle instability? Clinical Journal of Sport Medicine, 22 (3), 228-33 PMID: 22504375

2 comments:

Jay Hertel said...

The author of the summary raises some important questions about the clinical utility of the the multiple hop test. If CAI status can be established based on injury history and patient self-report of functional status (as was done in this study), what is the added value of a functional performance test to discriminate between patients with and without CAI? I think this issue is amplified more if the functional performance test is not responsive to change as patient health status changes. While the authors report the MDC estimates for the multiple hop test measures, they didn't actually track changes in patient performance over time as part of this study. My suspicion is that this test, like the Star Excursion Balance Test, would actually improve with an adequate rehabilitation program. My personal opinion is that functional tests have greater clinical utility as outcome tools to track progress over time than as diagnostic tools.

Mark A. Rice said...

Jay, thanks for reading and commenting . I agree with all of the points that you bring up. Based upon the author's previous studies regarding the multiple hop test, I believe that that this study was the next logical step in determining its clinical utility. Thanks, again

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