Exploring the Links Between Human Movement, Biomechanics & Gait
Take good look at these gals. The gal on the left (in blue) looks like she has a level pelvis, but look at the upper body. She’s leaning to the left and has a great deal of torso rotation backward. One of the clues is the abduction of her left arm. Also note how her right arm crosses across her body. We wonder how she looks in right foot stance.
The gal on the left (in red) has a subtle dip of the right side of her pelvis and also has over rotation of her upper body. Her right on crossing the body is a good reason to believe she will have a crossover gait if viewed from straight on.
While both of these gals may have adequate strength, we question how much endurance they have as well as available rotation in the hips and lumbar spine.
This is an excellent, referenced review of some of the current literature and controversy of strength and injury risk. A good read and certainly worth your time to get caught up on what’s current. We would love to see you study on endurance and injury risk.
“While muscle strength may improve tolerance of loads during running, another reason for inconsistencies in the reported relationships between strength and injury risk may be that strength is typically assessed isometrically. It’s unclear how much of an influence peak isometric strength has on the dynamic task of running, and specifically on prolonged running in the presence of muscular fatigue. Schmitz et al found that, while isometric hip strength values were similar between novice and experienced runners, hip internal rotation motion during running was higher in the novice runners, suggesting isometric strength may not correlate strongly with muscular control and kinematics during running.”
Arm swing asymmetry: It can be a huge window of education into your client, if you can get past the dumb stuff we’ve all done (and believed) for decades. I have beaten you down with arm swing principles over the past few years, sorry about that, but, the beating will continue because it is important to know what arm swing tells you, and what it does not tell you (hint hint for all those improperly coaching arm swing changes). We did an entire tele seminar on the Stage 1 principles of of arm swing (#218) on www.onlinece.com and www.chirocredit.com if you wish to take that archived lecture. Heck $19, how can you lose (see photo). Arm swing is intimately dependent upon scapular stability, thoracic mobility, breathing, cervical spine function, pelvis stability and clearly ipsilateral and contralateral leg swing not to forget to mention spinal stability. The first signs of spine pain or instability and the counter rotation of the shoulder and pelvic girdles become more phasic, instead of their normal anti phasic nature (moving in opposite directions). This phasic nature reduces spinal shear loads.
Neurologic diseases in their early, middle and late phases can give us a clearer window into how the nervous system is tied together. Arm swing asymmetry during gait may be a sensitive sign for early Parkinson’s disease.
Here is what this Plate et al study found : -Arm swing amplitude as well as arm swing asymmetry varied considerably in the healthy subjects. -Elderly subjects swung their arms more than younger participants. -Only the more demanding mental load caused a significant asymmetry -In the patient group, asymmetry was considerably higher and even more enhanced by mental loads. -Evaluation of arm swing asymmetry may be used as part of a test battery for early Parkinson’s disease.
Some facts you should consider: Parkinson’s Disease will be well advanced before the first signs of motor compromise occurs. So early detection and suspicion should be acted upon early when possible. Reductions or changes in arm swing may be the first signs of neuralgic disease expression and progression. Dual tasking may bring out neurologic signs early, so talk to your clients or have them count backwards to distract the motor programs. Look for one sided arm swing impairment, and when present, be sure to examine all limbs, especially the lower limbs, for impaired function. After all, the arms are like balasts, they can help with postural stability simply by abducting or modifying their swing. Arm swing changes can include: – crossing over the body – more forward sagittal swing and less posterior swing – more posterior sagittal swing and less anterior swing – shoulder abduction during swing (and with attributes of the prior two mentioned above) – less swing with adduction stabilized with torso – modified through accentuations or dampening of shoulder girdle rotation oscillations, thus less arm swing but more torso swing to protect the glenohumeral and other joints – and others of course
Arm swing and arm swing symmetry matter. Don’t be a dunce and just train it out or tell your client to do things to change it before you identify the “why” behind it. If it were that simple Ivo and I would have long grown tails and begun eating more bananas. Or maybe we would have already moved to the islands by now. That was random wasn’t it. That’s what Jimmy Buffett said.
“Now he lives in the islands, fishes the pilin’s And drinks his green label each day He’s writing his memoirs and losing his hearing But he don’t care what most people say. Through eighty-six years of perpetual motion If he likes you he’ll smile then he’ll say Jimmy, some of it’s magic, some of it’s tragic But I had a good life all the way. And he went to Paris looking for answers To questions that bother him so.” -Jimmy Buffett
Hope this helps, now back to that rum. -Shawn Allen
Gait Posture. 2015 Jan;41(1):13-8. doi: 10.1016/j.gaitpost.2014.07.011. Epub 2014 Aug 8. Normative data for arm swing asymmetry: how (a)symmetrical are we? Plate A1, Sedunko D2, Pelykh O3, Schlick C4, Ilmberger JR5, Bötzel K6. http://www.ncbi.nlm.nih.gov/pubmed/25442669
It is Rewind Friday. Today, we are reaching back to a brief 2009 lecture I did for the local NSCA chapter on the patterns of kinetic chain compensation that match with loss of medial and lateral foot tripod. (video starts at 49 seconds, for some reason) https://www.youtube.com/watch?v=yeCBGZkNaeM
5mm cut off ? MaybeYou are likely to come across hip and knee arthroplasty clients (total joint replacements). When they take a joint out and replace it with a new one, it can be a true challenge to restore leg lengths to equality side to side. Problems often arise down the road once gait is resumed and rehabilitation is completed. It can take time for the leg length discrepancy (LLD) to begin to create compensatory problems. This article seems to suggest that 5mm is the tipping point where gait changes becoming a problem are founded. Other sources will render different numbers, this article found 5mm. The authors found that both over- and underrestoration of leg length/offset showed similar effects on gait and that Gait analysis was able to assess restoration of biomechanics after hip replacement. I would chose to use the word “change” over restore, since the gait analysis is merely showing the deployed strategies and compensations, never the problem. But it is a tool, and gait analysis can be a decent tool to show “change”.*Remember, it is not always a product of true length, it can come from the pelvis posturing and/or from the acetabular orrientation, which can be a postoperative sequella. One cannot over look acetabular inclination, anteversion and femoral component anteversion/retroversion issues.Just remember, before you start making LLD changes with inserts, cork, orthotics etc be sure that you have restored as best as possible, pelvis-hip-spine mechanics because changes here can reflect as a mere leg length discrepancy. And it goes the other way as well, a LLD can cause those changes above.
* Just use your brain and don’t just lift the heel, give them a full sole lift. Heel lifts for this problem are newbie mistakes. Don’t be a newbie.
Below you will find an article on footwear and running. Rice et al concluded that
“ When running in a standard shoe, peak resultant and component instantaneous loadrates were similar between footstrike patterns. However, loadrates were lower when running in minimal shoes with a FFS (forefoot strike), compared with running in standard shoes with either foot strike. Therefore, it appears that footwear alters the loadrates during running, even with similar foot strike patterns.
They concluded that footwear alters the load rates during running. No brain surgery here. But that is not the point I want to discuss today. Foot strike matters. Shoes matter. And pairing the foot type and your strike patterns of mental choice, or out of natural choice, is critical. For example, you are not likely (hopefully) to choose a HOKA shoe if you are a forefoot striker. The problem is, novice runners are not likely to have a clue about this, especially if they are fashonistas about their reasoning behind shoe purchases. Most serious runners do not care about the look/color of the shoe. This is serious business to them and they know it is just a 2-3 months in the shoe, depending on their mileage. But, pairing the foot type, foot strike pattern and shoe anatomy is a bit of a science and an art. I will just mention our National Shoe Fit Certification program here if you want to get deeper into that science and art. (Beware, this is not a course for the feint of heart.)
However, I just wanted to approach a theoretical topic today, playing off of the “Forefoot strike” methodology mentioned in the article today. I see this often in my practice, I know Ivo does as well. The issue can be one of insufficient endurance and top end strength (top end ankle plantar flexion) of the posterior mechanism, the gastrocsoleus-achilles complex. If your calf complex starts to fatigue and you are forefoot striker, the heel will begin to drop, and sometimes abruptly right after forefoot load. The posterior compartment is a great spring loading mechanism and can be used effectively in many runners, the question is, if you fatigue your’s beyond what is safe and effective are you going to pay a price ? This heel drop can put a sudden unexpected and possibly excessive load into the posterior compartment and achilles. This act will move you into more relative dorsiflexion, this will also likely start abrupt loading the calf-achilles eccentrically. IF you have not trained this compartment for eccentric loads, your achilles may begin to call you out angrily. Can you control the heel decent sufficiently to use the stored energy efficiently and effectively? Or will you be a casualty? This drop if uncontrolled or excessive may also start to cause some heel counter slippage at the back of the shoe, friction is never a good thing between skin and shoe. This may cause some insertional tendonitis or achilles proper hypertrophy or adaptive thickening. This may cause some knee extension when the knee should not be extending. This may cause some pelvis drop, a lateral foot weight bear shift and supination tendencies, some patellofemoral compression, anterior meniscofemoral compression/impingement, altered arm swing etc. You catch my drift. Simply put, an endurance challenged posterior compartment, one that may not express its problem until the latter miles, is something to be aware of.
Imagine being a forefoot striker and 6 miles into a run your calf starts to fatigue. That forefoot strike now becomes a potential liability. We like, when possible, a mid foot strike. This avoids heel strike, avoids the problems above, and is still a highly effective running strike pattern. Think about this, if you are a forefoot striker and yet you still feel your heel touch down each step after the forefoot load, you may be experiencing some of the things I mentioned above on a low level. And, you momentarily moved backwards when you are trying to run forwards. Why not just make a subtle change towards mid foot strike, when that heel touches down after your forefoot strike, you are essentially there anyways. Think about it.
Shawn Allen, one of The Gait Guys
Footwear Matters: Influence of Footwear and Foot Strike on Loadrates During Running. Medicine & Science in Sports & Exercise: Rice, Hannah M.; Jamison, Steve T.; Davis, Irene S.
More on landing mechanics. Here is a recent article on landing mechanics. This article talks about the landing mechanics far past where I feel the first stage of vulnerability is, which is initial forefoot load, as i discuss in the video pertaining to landing from a jump or if sprinting (forefoot loading). IF landing occurs in low gear (lateral half of the forefoot), inversion risks are higher. The medial foot tripod, high gear toe off (1st and 2nd mets) is where we should be taking off from, and landing initially upon. Anything lateral is vulnerable without the lateral column strength (lateral gastrocsoleus complex, peronei longus/brevis). This article talks about knee flexion angles and ACL vulnerability, far after this initial loading response. The article some valid conclusions in that phase.
One point and 1 treatment can profoundly influence gait
When talking about the lower extremity and gait (as I have been know to do at more that one seminar), I often talk about the “reverse engineering” principle. This is looking at a muscle or muscle group from a “ground up” perspective, as it would be functioning during the gait cycle. This, along with knowing when a muscle should be firing in the gait cycle, can provide clues to what may be going on and how you may be able to help.
When discussing the quads, we often employ this principle. It can be a little difficult to think of the vastus medialis as a lateral rotator of the thigh and the rectus femoris as a flexor (anterior nutator) of the pelvis, but if you put your foot on the ground and think about it, you will see what I mean.
The VMO is often implicated in patello femoral syndromes but cannot be selectively activated. The ratio between vastus medialis and vastus lateralis does seem to be alterable and perhaps is a siginificant factor.
How about if we look at the vastus lateralis instead?
The vastus lateralis is the largest and most powerful portion of the quadriceps. One paper reports that the muscle volume of the the vastus lateralis was 674 cm3 followed by the vastus intermedius at 580 cm3, vastus medialis 461 cm3 and lowest in the rectus femoris 339 cm3. This makes the vastus lateralis is twice the volume of the rectus femoris!
Studies of muscle fiber orientation show that VL force component is directed approximately 12-15° laterally with respect to the longitudinal axis of the femoral shaft. This would mean it has a tremendous mechanical advantage and could (should?) pull the patella directly laterally compared to the VMO force, whose component is directed approximately 55 ° medially. The muscle “balance” between the VMO and the VL, along with the periarticular soft tissue structures acting on the patella, is considered major component in the control of normal patellar alignment and function. The VL is often considered to be the “overactive” one by many clinicians, particularly in cases of patellofemoral dysfunction. It turns out that from an EMG standpoint, they may be correct.
The vastus lateralis arises posteriorly from the femur along the linea aspera and circumnavigates the thigh in a counterclockwise fashion to attach laterally to the patellar tendon. Because of its size and fiber orientation, it would stand to reason that needling it would have more cortical representation than say the vastus medialis.
There is an interesting paper where they needled a single acupuncture point: Stomach 34. For those who haven’t studied acupuncture (or don’t remember) this point is located on the thigh, in a small depression about 2.5 inches (63 mm for the metric folks) lateral to and above lateral border of the patella. In other words, it is in the vastus lateralis (see above).
The results showed statistically significant improvement in velocity, cadence, stride length, cycle time, step time and single/double leg support after treatment. The effect was small, but positive.
Think about where the trigger points are for this muscle (see above) ; fairly close to this point, sometimes (depending on the trigger point), even directly over this point. Needling has many effects on muscle and its trigger points and we like to think that needling “normalizes” function of a muscle; perhaps it influences the apparent “dominance” of this muscle and allows the patella to track more medially?
So, in this popultion of patients of elderly individuals, 1 acupuncture (needling) treatment had a positive influence on their gait. Perhaps if the folks in the knee study were treated a few more times, we would have seen a change. Imagine what could have happened if aditional treatment modalities, like exercise, proprioceptive work and gait retraining were added!
What a great, cost effective alternative or addition to your rehabilitation this could be. Consider adding this modality (and point!) to your current clinical toolbox, not only for older patients but for any patients that may have a gait abnormality.
Kim, H. H., & Song, C. H. (2010). Effects of knee and foot position on EMGactivity and ratio of the vastus medialis oblique and vastus lateralis during squatexercise. Journal of Muscle and Joint Health, 17(2), 142-150.
Lam, P. L., & Ng, G. Y. (2001). Activation of the quadriceps muscle during semisquatting with different hip and knee positions in patients with anterior knee pain. American Journal of Physical Medicine & Rehabilitation, 80(11), 804-808.
Erskine, R. M., Jones, D. A., Maganaris, C. N., & Degens, H. (2009). In vivo specific tension of the human quadriceps muscle. European journal of applied physiology, 106(6), 827-838. [PubMed]
Grabiner MD: Current Issues in Biomechanics (9th ed). Champaign, Human Kinetics Publishers, 1993.
Keep these things in mind when you are doing a treadmill gait analysis. We have discussed over and over again of the severe and misleading information gleaned from gait analysis, that it shows strategies around problems, often not the problem at hand. But, this is yet one more factor to keep in mind when you are doing such studies, that changing the surface and how and why any given work is being performed on a given surface/device, that the information can be tainted if you do not know exactly what you are dealing with.
Few studies are perfect, look at all of the parameters they likely should, and understand the complexity of the model they examine in their entirety. None the less, there is information to glean from most studies that help to debate, refute or clarify working concepts presently proven or unproven. This study provides some conclusions as well, that should be take in, digested and then determined where, when and if appropriate for a client.
Tibial impacts and muscle activation during walking, jogging and running when performed overground, and on motorised and non-motorised treadmills
A clear cut case of Form follows Function. Leave a deforming force long enough and the body will accommodate.
When the lateral quadratus plantae (QP) is weak and the flexor digitorum longus pulls unopposed (relying on the QP to properly orient the long flexor pull) for too long the 4th and 5th toes and drift medially and spin inwards toward the midline of the foot (as seen in the photo). Then, as the 4th toe presses down on the fleshy pad of the 5th toe, over time the fleshy pad is pancaked and triangulated. Then, with repeated pressure a corn like hardness becomes of the tip of that triangluted tissue, it resembles a hard callus. A corn is a coalescing of the skin cells into a tighter formation, a reaction to fend off repeated pressure and friction. Form follows prolonged function. Shave these things down and they will come back, unless you get to the root source of the problem, which could be all the way up the chain.