ESMAC 2012 abstract / Gait & Posture 38 (2013) S1–S116 S89 particular DT interference. GPS and particularly its MAP decompo- sition may be useful for clinical practice and provide information about the changes in movement pattern. Further reading [1] O’Shea S, et al. Physcal Therapy 2002;82:888–97. [2] Baker R, et al. Gait&Posture 2009;30:265–9. [3] Beynon S, et al. Gait&Posture 2010;32:129–32. [4] Baker R, et al. Gait&Posture 2012;35:612–5. http://dx.doi.org/10.1016/j.gaitpost.2013.07.184 P02 Are effects of the symmetric and asymmetric tonic neck reflexes still visible in healthy adults Sjoerd M. Bruijn, Firas Massaad, Leen Van Gestel, Jacques Duysens Department of Kinesiology, K.U.Leuven, Motor Control Laboratory, Research Center for Movement Control and Neuroplasticity, Leuven, Belgium Introduction: In 1924 Magnus [1] was the first to describe that when a cat’s head is rotated in a transverse plane to one side, the legs on that side of the body extended, while on the other side, they flexed (Asymmetric Tonic Neck Reflexes). On the contrary, when the head was rotated in a sagittal plane both legs flexed when the head flexed, and they extended when the head extended (Symmet- ric Tonic Neck Reflexes). These so called Asymmetric/Symmetric Tonic Neck Reflexes were later found to also exist in newborn babies [2], and are thought to be a motor primitive, which is suppressed later in life. Still, using a test in which children sit on hand and knees, and rotate their head to left and right, Parr et al. [3] were able to show that effects of the ATNR can be found in children up to 9 years of age. This is interesting, as it may suggest that these reflexes may still be involved in motor control in these children. Whether this is also the case in full- grown adults was investigated by Hellebrandt et al. [4] who reported clear effects of the ATNR. However, the methods used in the latter study were rather coarse, relying on photograms of subjects. Thus, for the current study, we set out to measure in detail whether the ATNR/STNR can still be evoked in healthy adult subjects. We did so with the future aim to look at the role of the ATNR/STNR in motor control during everyday movements, such as walking while looking in another direction. Patients/materials and methods: We measured 10 subjects (8 males, age: 22.2 ± 3.1 years length: 1.77 ± 0.1 m mass: 70.5 ± 12.9 kg). Subjects were asked to sit on their hands an knees while (1) Their head was flexed and extended by an experimenter, (2) they were asked to actively flex and extend their head, (3) their head was rotated left and right by an experimenter, (4) they were asked to actively rotate their head left and right. For each of these movements, three repetitions were performed and each movement was maintained around 5 seconds at the end. Kinematics were reg- istered using a Vicon system (Plugingait fullbody markerset). Elbow and head angles were detrended, and a regression analysis was performed, to investigate the effects of head angle on elbow angle. Results: For both conditions involving flexion/extension move- ments of the head (i.e. active and passive flexion/extension), positive regression coefficients were found for all subjects, indicat- ing that subjects flexed the elbows when the head was flexed, and extended them when the head was extended. For both active and passive rotations however, the left elbow showed a positive regres- sion coefficient, while the right elbow showed a negative regression coefficient, indicating that the left arm extended when the head turned left, and flexed when the head turned right, while the right arm did the opposite, as predicted by the ATNR. Discussion & Conclusions: We were able to precisely quantify the existence of the ATNR and STNR in adult subjects. A next step will be to assess the effects of the ATNR and STNR during everyday motor control tasks, such as walking while looking in a different direction. FRIDAY P2 Sjoerd Bruijn 204 P4 Zahra Rojhanishirazi 205 P6 Christian Wyss 206 P8 Oliver Rettig 207 P10 Christophe Meyer 208 P12 Zahra Rojhanishirazi 209 P14 Shavkat Kuchimov 210 P16 Benita Kuni 211 P18 Ambreen Chohan 212 P20 Mark Kasmer 213 P22 Loreen Pogrzeba 214 P24 Ellen Jaspers 215 P26 Maria Gomez 216 P28 Andrzej Mastalerz 217 P30 Alexandra Halvarsson 218 P32 Helena Grip 219 P34 Anna Trulsson 220 P36 Irene Rodríguez 221 P38 Silvestris Zebolds 222 P40 Helena Grip 223 P42 Yoshimasa Sagawa Jr 224 P44 Amir Al-Munajjed 225 P46 Thomas Dreher 226 P48 Marilynn Wyatt 227 P50 Nancy Thesing 228 P52 Christian Beyaert 229 P54 Ambreen Chohan 230 P56 Silvia Del Din 231 P58 Silvio Garbelotti Jr 232 P60 Małgorzata Ogurkowska 233 P62 Małgorzata Ogurkowska 234 P64 Jung Hwan Lee 235 P66 Ailish Malone 236 P68 Jung Hwan Lee 237 P70 Jo Røislien 238 P72 Christian Wyss 239 P74 Ambreen Chohan 240 P76 Jaap Harlaar 241 P78 Stefano Rossi 242 P80 Barbara Callewaert 243 P82 Ana Presedo 244 P84 Bing-Shiang Yang 245 P86 Tobias Stenlund 246 P88 Alberto Rigato 247 P90 Tim Weber 248 P92 Barbara Callewaert 249 P94 Marianna Romei 250 P96 Nikolaos Darras 251 P98 Mohsen Razeghi 252 P100 Mohsen Razeghi 253 References [1] Magnus R. Korperstellung. Berlin: Julius Springer; 1924. [2] Gesell A. The tonic neck reflex in the human infant. Journal of Pedriatics 1938;13:455. [3] Parr C, Routh DK, Byrd MT, McMillan J. A developmental study of the asymmet- rical tonic neck reflex. Dev Med Child Neurol 1974;16:329–35. [4] Hellebrandt FA, Schade M, Carns ML. Methods of evoking the tonic neck reflexes in normal human subjects. Am J Phys Med 1962;41:90–139. http://dx.doi.org/10.1016/j.gaitpost.2013.07.185