From time to time we get asked, why have you guys focused so intently on gait ? Our answer is always the same. It is the most frequently engaged motor pattern that the body does other than breathing. Without the ability to walk our health declines on many levels. And, because gait impacts every aspect of the human organism when it comes to locomotion. All too often gait is thought of as what the feet are doing. We see this as evidenced by how many shoe stores still just do a foot treadmill video analysis, but thankfully, many stores have gotten the message from somewhere that the rest of the body is vital to the assessment as well. However, how many of you are capturing the head on your gait analysis ? The head is where the software exists. Balance, visual, many proprioceptive centers, auditory and the processing of these and more are all located north of all of the other body parts.
We have done many previous blog posts on the visual and auditory centers and how they impact gait. You can goto our blog and type these into our SEARCH box and read more about these topics however today we wanted to share with you an article that is a few years older to show that there are many predictive gait parameters that are pre-calculated and have a huge determining effect and outcome on one’s gait.
Anticipatory head movements during turns, whether running on a banked track, taking tight turns on your local road, trail running on the side of slopes or even when biking and trail riding, all occur in order to gather advance visual information about the trajectory and potential obstacles. Below is an abstract that pretty much speaks for itself and you should read it. In the study they investigate the relationship between head and trunk movements during ambulation. They discuss how the head makes its calculated turn prior to the trunk turning, setting up the body for a proper negotiation of the banking of the turn thus gathering “visual information about the trajectory and potential obstacles”.
If you are truly a gait geek, you should get a little warm and fuzzy about this. And if you do not, well, you might still be a gait geek if you think a bit further about this and understand that cervical spine stability and mobility can negatively or positively affect the outcome. It just goes to prove once again, if you are going to address someones gait, you better have a clinical examination as part of their gait assessment if you want to truly find out where their impairment exists, and hides. If you depend solely on video, you are most likely giving advice on missing information, this we pretty much promise you. For example, we recall a younger lady from a few years ago, a patient of ours, who was left with unilateral deafness from a vaccine complication (MMR vaccine). She would always have her better ear turned more forward to gain an auditory edge to her hearing loss on the opposite side (we all do the same thing when we are talking to someone in a loud place). What we noticed, and what she was unaware of, what that this impaired her arm swing bilaterally making the one side swing more and the other less (which was a huge clue into her shoulder problem that she was seeing us for). This in turn, because they are neurologically connected by reflexive locomotion patterns, impaired swing and stance phases of her gait on both sides. It just goes to prove our point earlier, and to further make the point that, you cannot impact symmetry in one place and not expect that the body will not compensate for that asymmetry elsewhere. It is all connected … . you know the song.
If you are a gait geek, you can see the entire picture of the human organism clearer than many others.
Enjoy the whole abstract below for the great details by Sreenivasa et al.
* Shawn and Ivo …….. not your average wild and crazy guys……unless there is a gait topic to talk about.
Exp Brain Res. 2008 Nov;191(3):313-20. doi: 10.1007/s00221-008-1525-3. Epub 2008 Aug 8.
Walking along curved paths of different angles: the relationship between head and trunk turning.
Sreenivasa MN, Frissen I, Souman JL, Ernst MO.
Source
Max Planck Institute for Biological Cybernetics, Spemannstrasse 41, 72076 Tübingen, Germany.
Abstract
Walking along a curved path requires coordinated motor actions of the entire body. Here, we investigate the relationship between head and trunk movements during walking. Previous studies have found that the head systematically turns into turns before the trunk does. This has been found to occur at a constant distance rather than at a constant time before a turn. We tested whether this anticipatory head behavior is spatially invariant for turns of different angles. Head and trunk positions and orientations were measured while participants walked around obstacles in 45 degrees, 90 degrees, 135 degrees or 180 degrees turns. The radius of the turns was either imposed or left free. We found that the head started to turn into the direction of the turn at a constant distance before the obstacle (approximately 1.1 m) for turn angles up to 135 degrees . During turns, the head was consistently oriented more into the direction of the turn than the trunk. This difference increased for larger turning angles and reached its maximum later in the turn for larger turns. Walking speeds decreased monotonically for increasing turn angles. Imposing fixed turn radii only affected the point at which the trunk started to turn into a turn. Our results support the view that anticipatory head movements during turns occur in order to gather advance visual information about the trajectory and potential obstacles.
