On 2015 Sep 20, Eythor Kristjansson commented:

The paper (Meisingset et al. BMC Musculoskeletal Disorders (2015) 16:56 DOI 10.1186/s12891-015-0517-2) reports the findings of a cross-sectional study, which examined set of tests to investigate cervical motor control. One of the tests that were used was the Fly Test©, which Meisingset et al cited “as described by Kristjansson et al., 2010” [1]. When I read the abovementioned article by Meisingset et al., [1] I found out that their article does not replicate the study by Kristjansson & Oddsdottir 2010, at all [2]. There are two main crucial differences in Meisingset et al. study and the original study by Kristjansson & Oddsdottir, 2010 [2], which make these 2 studies incomparable. First, there are several inbuilt parameters in the patterns in the original Fly Test©, and it is impossible for Meisingset et al., to know what inbuilt parameters were used and how we used these parameters. Meisingset et al. just copied the geometry of 2 patterns without permission from the publisher. Second, Meisingset et al. methodology is completely different from ours. Research results using different inbuilt variables within the patterns and completely different methodology can never be comparable. It is therefore not surprising that Meisingset et al. study found no difference in the performances between controls and neck pain group, besides that the controls performed worse in one sequence of what Meisingset et al., misleadingly call “the Fly Test”. Following are the main differences in methodology of the 2 studies: 1. Set-up: Our original study used a seated position, 1m from the screen whereas Meisingset et al. used standing position, 2.5m from the screen. It can be easily proven mathematically that different angles are produced on the screen depending on the patients distance from the screen. This alone will generate different results as longer distance (2.5 m) will produce narrower angle on the screen i.e. lesser ROM than a distance of 1m, as we used in our original paper. 2. Number of patterns and repetitions: Our original study used three patterns, easy-medium-difficult of uniform size and three repetitions for each pattern in random order, altogether 9 trials. Meisingset et al. used two patterns, easy and medium with 2 trajectory sizes; on smaller and one bigger. Furthermore, the control group in Meisingset et al study just performed the patterns once, while the neck pain group performed the patterns twice, not in random order. 3. Duration of patterns: Our original study used 25, 40, and 50 seconds for the easy-medium-difficult patterns, respectively whereas Meisingset et al. used 30 seconds for both patterns; easy and medium. Here, Meisingset et al. wrongly cited our original paper; see Table 1 in their study [1]. The velocity in Meisingset et al. study for the medium pattern must therefore be faster than in the easy pattern as longer distance is traveled in the medium pattern. I have one more serious concern about Mesingset et al. conclusion regarding what they misleadingly call “the Fly Test” in their study: In the Discussion section, Meisingset et al. cited Oddsdottir et al. 2013, regarding gender difference. Meisingset et al. write on p. 11 under the heading Trajectory movement control: “In the HC group (Healthy Control) we found that females had a consistently larger deviation in the Fly test compared to men in the HC group suggesting that the group differences in Kristjansson & Oddsdottir study, 2010 may be influenced by the different gender distribution in the groups”. Meisingset et al. continue: “However, Oddsdottir et al. found similar results between healthy females and men for the same Fly test [3]”. “This discrepancy between the studies requires further investigation before this test can be implemented in clinical practice.” Meisingset et al. are making reference to our database study [3]. The result section on p. 3 in our database study starts on the following statement: “The multivariate analysis of variance indicated a statistically significant effect for age (p < 0.001), but not for gender (p > 0.05). Therefore normative data were only distributed according to age”. It is impossible for us to understand how Meisingset et al. can cite our work in such a wrong way. References [1] Meisingset I, Woodhouse A, Stensdottir A-K, Stavdahl Ö, Lorås H, Gismervik S, Andersen H, Austreim K, Vasseljen O, Evidence for a general stiffening motor control pattern in neck pain: a cross sectional study. BMC Musculoskeletal Disorders (2015) 16:56 DOI 10.1186/s12891-015-0517-2 [2] Kristjansson E, Oddsdottir G."The Fly" - A new clinical assessment and treatment method for deficits of movement control in the cervical spine: reliability and validity. Spine 2010; 35: E1298–E1305 [3] Oddsdottir G, Kristjansson E, Gislason M. Database of movement control of the cervical spine: Reference normal of 182 asymptomatic people. Manual Therapy 2013; 18: 206–210.

Competing interests: EK is the founder of NeckCare Ltd, a start-up innovation company developing the Fly Method©, and other innovative methods, for diagnostic and treatment purposes. The tasks created in the new Fly Method© are protected by patent rights.

Meisingset I, 2015 http://www.nih.gov NIH Home

On 2015 Sep 20, Eythor Kristjansson commented:

The paper (Meisingset et al. BMC Musculoskeletal Disorders (2015) 16:56 DOI 10.1186/s12891-015-0517-2) reports the findings of a cross-sectional study, which examined set of tests to investigate cervical motor control. One of the tests that were used was the Fly Test©, which Meisingset et al cited “as described by Kristjansson et al., 2010” [1]. When I read the abovementioned article by Meisingset et al., [1] I found out that their article does not replicate the study by Kristjansson & Oddsdottir 2010, at all [2]. There are two main crucial differences in Meisingset et al. study and the original study by Kristjansson & Oddsdottir, 2010 [2], which make these 2 studies incomparable. First, there are several inbuilt parameters in the patterns in the original Fly Test©, and it is impossible for Meisingset et al., to know what inbuilt parameters were used and how we used these parameters. Meisingset et al. just copied the geometry of 2 patterns without permission from the publisher. Second, Meisingset et al. methodology is completely different from ours. Research results using different inbuilt variables within the patterns and completely different methodology can never be comparable. It is therefore not surprising that Meisingset et al. study found no difference in the performances between controls and neck pain group, besides that the controls performed worse in one sequence of what Meisingset et al., misleadingly call “the Fly Test”. Following are the main differences in methodology of the 2 studies: 1. Set-up: Our original study used a seated position, 1m from the screen whereas Meisingset et al. used standing position, 2.5m from the screen. It can be easily proven mathematically that different angles are produced on the screen depending on the patients distance from the screen. This alone will generate different results as longer distance (2.5 m) will produce narrower angle on the screen i.e. lesser ROM than a distance of 1m, as we used in our original paper. 2. Number of patterns and repetitions: Our original study used three patterns, easy-medium-difficult of uniform size and three repetitions for each pattern in random order, altogether 9 trials. Meisingset et al. used two patterns, easy and medium with 2 trajectory sizes; on smaller and one bigger. Furthermore, the control group in Meisingset et al study just performed the patterns once, while the neck pain group performed the patterns twice, not in random order. 3. Duration of patterns: Our original study used 25, 40, and 50 seconds for the easy-medium-difficult patterns, respectively whereas Meisingset et al. used 30 seconds for both patterns; easy and medium. Here, Meisingset et al. wrongly cited our original paper; see Table 1 in their study [1]. The velocity in Meisingset et al. study for the medium pattern must therefore be faster than in the easy pattern as longer distance is traveled in the medium pattern. I have one more serious concern about Mesingset et al. conclusion regarding what they misleadingly call “the Fly Test” in their study: In the Discussion section, Meisingset et al. cited Oddsdottir et al. 2013, regarding gender difference. Meisingset et al. write on p. 11 under the heading Trajectory movement control: “In the HC group (Healthy Control) we found that females had a consistently larger deviation in the Fly test compared to men in the HC group suggesting that the group differences in Kristjansson & Oddsdottir study, 2010 may be influenced by the different gender distribution in the groups”. Meisingset et al. continue: “However, Oddsdottir et al. found similar results between healthy females and men for the same Fly test [3]”. “This discrepancy between the studies requires further investigation before this test can be implemented in clinical practice.” Meisingset et al. are making reference to our database study [3]. The result section on p. 3 in our database study starts on the following statement: “The multivariate analysis of variance indicated a statistically significant effect for age (p < 0.001), but not for gender (p > 0.05). Therefore normative data were only distributed according to age”. It is impossible for us to understand how Meisingset et al. can cite our work in such a wrong way. References [1] Meisingset I, Woodhouse A, Stensdottir A-K, Stavdahl Ö, Lorås H, Gismervik S, Andersen H, Austreim K, Vasseljen O, Evidence for a general stiffening motor control pattern in neck pain: a cross sectional study. BMC Musculoskeletal Disorders (2015) 16:56 DOI 10.1186/s12891-015-0517-2 [2] Kristjansson E, Oddsdottir G."The Fly" - A new clinical assessment and treatment method for deficits of movement control in the cervical spine: reliability and validity. Spine 2010; 35: E1298–E1305 [3] Oddsdottir G, Kristjansson E, Gislason M. Database of movement control of the cervical spine: Reference normal of 182 asymptomatic people. Manual Therapy 2013; 18: 206–210.

Competing interests: EK is the founder of NeckCare Ltd, a start-up innovation company developing the Fly Method©, and other innovative methods, for diagnostic and treatment purposes. The tasks created in the new Fly Method© are protected by patent rights.

Meisingset I, 2015 http://www.nih.gov NIH Home