XBox and gait analysis

The revised Xbox One Kinect, also known as the Microsoft Kinect V2 for Windows, includes enhanced hardware which may improve its utility as a gait assessment tool.
“In conclusion, while the Kinect V2 body tracking may not accurately obtain lower body kinematic data, it shows great potential as a tool for measuring spatiotemporal aspects of gait.”

J Biomech. 2015 May 28. pii: S0021-9290(15)00298-5. doi: 10.1016/j.jbiomech.2015.05.021. [Epub ahead of print]
Gait assessment using the Microsoft Xbox One Kinect: Concurrent validity and inter-day reliability of spatiotemporal and kinematic variables.
Mentiplay BF

The gluteus medius and low back pain.

We see this one ALL the time. We are sure you do as well.
“Gluteus medius weakness and gluteal muscle tenderness are common symptoms in people with chronic non-specific LBP.”
It is often more on the side of pelvic frontal plane drift. The abdominals and spinal stabilizers also often test weak on this same side. We often see compromise of hip rotation stability as well because , since the hip is relatively adducting (because the pelvis is undergoing repeated frontal plane drift, hence no hip abduction) there is often a component of cross over gait phenomenon which can threaten rotation stability of the lower limb (type “cross over gait” into the search box of our tumblr blog for a landslide of work we have written on that phenomenon).

Eur Spine J. 2015 May 26. [Epub ahead of print]
Prevalence of gluteus medius weakness in people with chronic low back pain compared to healthy controls.
Cooper NA1, Scavo KM, Strickland KJ, Tipayamongkol N, Nicholson JD, Bewyer DC, Sluka KA.

http://www.ncbi.nlm.nih.gov/pubmed/26006705

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Abs on the UP, Glutes on the DOWN

I had the opportunity to go on my 1st mountain bike ride of the season last Sunday morning. Yes, I am aware it is JUNE, but the snow has finally melted (we had over 7 FEET at arapahoe Basin in May) and you need to understand that I am usually a runner). In the cool morning 44 degree air I was reminded of the importance of my gluteal muscles (rather than just my quads) while climbing a technical hill which was clearly pushing my aerobic capacity. We have the opportunity to perform many bike fits in the office and treat many cycling ailments. We also train and retraing pedal stroke and one of our mantras (in addition to skill, endurance and strength) is “Glutes on the downstroke; Abs on the upstroke”. Meaning use your glutes to extend the hip from 12 to 6 o’clock and use your abs to initiate the upstroke. Quadricep (on the downtstroke) and hamstring dominance (on the upstroke) is something we see often and this mantra often proves useful in the “retraining process”.

I have been a fan of Ed Burkes work (“Serious Cycling” and “Competitive Cycling”) for years and have read (and lectured about) these books many times. In my effort to find a basis in the literature for my mantra, I ran across a paper (1) that seemed to substantiate, at least in part, the mantra. It is a small study looked at elite athletes that explores changes that occur in muscle recruitment as the body fatigues after a sub maximal exercise session.

Their conclusion “The large increases in activity for gluteus maximus and biceps femoris, which are in accordance with the increase in force production during the propulsive phase, could be considered as instinctive coordination strategies that compensate for potential fatigue and loss of force of the knee extensors (i.e., vastus lateralis and vastus medialis) by a higher moment of the hip extensors.”

This makes sense, although may be contradicted by this study (2), which showed LESS gluteal activity at higher mechanical efficiency, with increased tricep surae activity. They conclude “These findings imply that cycling at 55%-60% V˙O(2max) will maximize the rider’s exposure to high efficient muscle coordination and kinematics.”  Although this study looks at mechanical efficiency and the 1st lloks at muscle activity.

Being seated on a bike and having your torso, as well as hips flexed is not the most mechanically efficient posture for driving the glutes, but clinical observation seems to dictate that the less quad and hamstring dominant people are on the down and up stroke respectively, then the more pain free they are. This does not always equte to being the fastest, but it does equate to fewer injuries showing up in the office.

  1. Dorel S1, Drouet JM, Couturier A, Champoux Y, Hug F. Changes of pedaling technique and muscle coordination during an exhaustive exercise. Med Sci Sports Exerc. 2009 Jun;41(6):1277-86. doi: 10.1249/MSS.0b013e31819825f8.
  2. Blake OM1, Champoux Y, Wakeling JM.  Muscle coordination patterns for efficient cycling. Med Sci Sports Exerc. 2012 May;44(5):926-38. doi: 10.1249/MSS.0b013e3182404d4b.
Abductory twist in your gait ?Last night on our www.onlinece.com teleseminar we discussed some clinical applications and critical thinking of gait parameters and pathology. We discussed the dynamic gait pedograph below. Possible evidence of Abductor…

Abductory twist in your gait ?

Last night on our www.onlinece.com teleseminar we discussed some clinical applications and critical thinking of gait parameters and pathology. We discussed the dynamic gait pedograph below. Possible evidence of Abductory Twist gait pathology (video linkhttps://youtu.be/F3DHRoHrYOs). In this case, client had loss of internal hip rotation, but they sure love external rotation pivot at the ground interface, as the pedo shows here (more details were provided on the teleseminar last night).
*Fix the problem, retrain normal gait skills, add endurance and strength to the new gait pattern and you have a solution. Add an orthotic to treat what you see on the pedograph and you have a bandaid (and potentially/probably a problem down the road). You can’t fix a motor pattern compensation by forcing a compensatory fix. Get to the root of the problem, in this case hip and pelvic biomechanics ! It is all about mobility and stability ! 

Cross Fit: Gray Cooks thoughts

Always a good read, he is always on the mark.
Gray Cook talks about CrossFit, injury rates, and protecting both elite and amateur level CrossFit athletes.
We couldn’t agree more about the fact that CrossFit often prioritizes reps and time which can lead to fatigue and compensation in lifters, often corrupting and even neglecting technique. (yes, not everyone and not ever cross fit gym, but enough that its worthy of dialogue).
https://www.t-nation.com/t…/how-to-prevent-crossfit-injuries

Gait changes on a treadmill

Something to ponder on those days when getting outside it just impossible because of weather.
Athletes might respond to fatigue differently when running on a treadmill compared with overground conditions, where pace is typically more variable.
“Before halfway, step length increased and cadence decreased, whereas during the latter stages, there were significant decreases in impulse and maximum force. Contact time decreased and flight time increased continually, but otherwise most gait variables did not change. The changes in contact and flight times suggested that athletes altered their gait so that more time was spent airborne to allow the treadmill to pass under them. In general, however, the runners maintained their techniques throughout the run. ”

http://www.ncbi.nlm.nih.gov/m/pubmed/23860291/

Muscle activity

Does variability in muscle activity reflect a preferred way of moving or just reflect what they’ve always done? In this study it was found that there isn’t always this tight relationship between activity in the muscles and the movement we’re seeing.
“Clearly, locomotion is not as simple as we thought it was,” Foster said. “This decoupling – big changes in movement without corresponding changes in muscle activity – suggests there are other important factors going on and we need to better understand them if we want to reproduce these movements in prosthetics or robotics.”
Hmmmm. thoughts. this makes everything more interesting doesn’t it ?!

http://esciencenews.com/articles/2014/03/14/motion.and.muscles.dont.always.work.lockstep.researchers.find.surprising.new.study

Muscle activity and movement

“We expected to see a one-to-one correlation between the muscle activity and movements because motion is generally driven by muscles,” Higham said, “but as we changed the structure of their habitat and they changed their motions, we were surprised to find very few accompanying changes in muscle activity.”

Context-dependent changes in motor control and kinematics during locomotion: modulation and decoupling. Foster and Higham
http://www.ncbi.nlm.nih.gov/pubmed/24621949

Gait on slippery floors.

You seem to see a glossy wetness to the tile floor ahead of you in the supermarket. Is that just a really polished floor or is that water? Hey, it might be slippery, lets make some adaptive changes up there in the brain.
Postural and temporal gait adaptations, which affected ground reaction forces occur.
This study found that “statistically significant gait adaptations included reductions in stance duration (SD) and loading speed on the supporting foot, shorter normalized stride length (NSL), reduced foot-ramp angle and slower angular foot velocity at heel contact. As a result of these adaptations, anticipation of slippery surfaces led to significant changes in lower extremity joint moments, a reflection of overall muscle reactions.”
Significant gait changes occur when there is percieved risk of slipping, and in this study, “even though subjects were asked to walk as naturally as possible”.

Changes in gait when anticipating slippery floors.
Cham R, et al. Gait Posture. 2002.
http://www.ncbi.nlm.nih.gov/m/pubmed/11869910/

Reteaching sensory-motor patterns

Trying to reteach your client’s CNS new sensory-motor patterns so they can move better ? We like to say that the first few weeks are like paying down a mortgage, you do not own them, you are cerebrally renting those changes and barely paying down the principle. It takes focused work and time to truly own the changes so that they translate into better movement.
“Depending on the complexity of the activity, [experiments have required] four and a half months, 144 days or even three months for a new brain map, equal in complexity to an old one, to be created in the motor cortex.” -Swart
New connections and pathways are fragile and only through repetition and practice and focused attention can those connections be established enough to become habitual or default behaviors.

Neuroscience for Leadership: Harnessing the Brain Gain Advantage (The Neuroscience of Business). Tara Swart