diff --git a/fixtracks/utils/trackingdata.py b/fixtracks/utils/trackingdata.py
index 8fc2808..3d0ca19 100644
--- a/fixtracks/utils/trackingdata.py
+++ b/fixtracks/utils/trackingdata.py
@@ -171,16 +171,30 @@ class TrackingData(QObject):
         return orientations
 
     def bendedness(self, bodyaxis=None):
+        """
+        Calculate the bendedness of the body axis.
+        Parameters
+        ----------
+        bodyaxis : list of int, optional
+            Indices of the body axis coordinates to consider. If None, defaults to [0, 1, 2, 5].
+        Returns
+        -------
+        numpy.ndarray
+            Array of mean absolute deviations of the body axis points from the head-tail vector.
+        """
+        
         if bodyaxis is None:
             bodyaxis = [0, 1, 2, 5]
         bodycoords = self.coordinates()[:, bodyaxis, :]
+        bodycoords = np.concat((bodycoords, np.zeros((bodycoords.shape[0], len(bodyaxis), 1))), axis=2)
         head_tail_vector = bodycoords[:, -1, :] - bodycoords[:, 0, :]
-        head_tail_vector = head_tail_vector[:, np.newaxis ,:]  # cross-product only defined in space, not in 2D
-        head_tail_length = np.linalg.norm(head_tail_vector, axis=1, keepdims=True)  # pythagoras, length of head- tail connection
-        point_axis_vectors = bodycoords - head_tail_vector
-        deviations = np.cross(head_tail_vector, point_axis_vectors)/head_tail_length
-        deviation = np.mean(deviations, axis=1)
-        return deviation
+        point_axis_vector = bodycoords[:,:,:] - bodycoords[:, 0, :][:,np.newaxis,:]
+        htv = head_tail_vector[:,np.newaxis, :]
+        # Pythagoras, length of head- tail connection
+        head_tail_length = np.linalg.norm(head_tail_vector, axis=1, keepdims=True)
+        deviations = np.cross(htv, point_axis_vector)[:,:,-1] / head_tail_length
+        deviations = np.mean(np.abs(deviations), axis=1)
+        return deviations
 
     def __getitem__(self, key):
         return self._data[key]
@@ -236,8 +250,8 @@ def main():
     lengths = data.animalLength()
     frames = data["frame"]
     tracks = data["track"]
-    
-    # bendedness = data.bendedness()
+    bendedness = data.bendedness()
+
 
     embed()
     tracks = data["track"]