Sunday, March 13, 2011

Different Speeds have Different Meanings in our Bodies' Performance in Pain Every little thing in the complex systems that are us seems to impact every other thing - or at least a whole lot of other things.  Take speed.  Have you ever tried to do a familiar movement either really fast or really slow? Say whipping an egg in a bowl, making a shoulder circle, lifting a knee up and down. Speed changes performance, doesn't it? Something else we've seen change performance is pain: pain will change even what muscles get recruited,when, performing an action (Cools; Ferguson). Recent research has put pain and speed together to see what happens in normal walking mechanics.

I'm fascinated by the study because of how it reinforces how quickly we see systemic adapatations to the new demands of a change in the system: in this case, two changes: pain and various speeds.

The researchers used a standard protocol to induce DOMS at the knee. Perhaps not surprisingly, they found that with the DOMS effect up, different speeds showed different kinds of compromise.

Here's the abstract:
Eur J Appl Physiol. 2010 Nov;110(5):977-88. Epub 2010 Jul 29.
The effects of muscle damage on walking biomechanics are speed-dependent.
Tsatalas T, Giakas G, Spyropoulos G, Paschalis V, Nikolaidis MG, Tsaopoulos DE, Theodorou AA, Jamurtas AZ, Koutedakis Y.

Institute of Human Performance and Rehabilitation, Center for Research and Technology, Trikala, Thessaly, Greece.

The purpose of the present study was to examine the effects of muscle damage on walking biomechanics at different speeds. Seventeen young women completed a muscle damage protocol of 5 × 15 maximal eccentric actions of the knee extensors and flexors of both legs at 60°/s. Lower body kinematics and swing-phase kinetics were assessed on a horizontal treadmill pre- and 48 h post-muscle damaging exercise at four walking speeds. Evaluated muscle damage indices included isometric torque, delayed onset muscle soreness, and serum creatine kinase. All muscle damage indices changed significantly after exercise, indicating muscle injury. Kinematic results indicated that post-exercise knee joint was significantly more flexed (31-260%) during stance-phase and knee range of motion was reduced at certain phases of the gait cycle at all speeds. Walking post-exercise at the two lower speeds revealed a more extended knee joint (3.1-3.6%) during the swing-phase, but no differences were found between pre- and post-exercise conditions at the two higher speeds. As speed increased, maximum dorsiflexion angle during stance-phase significantly decreased pre-exercise (5.7-11.8%), but remained unaltered post-exercise across all speeds (p > 0.05). Moreover, post-exercise maximum hip extension decreased (3.6-18.8%), pelvic tilt increased (5.5-10.6%), and tempo-spatial differences were found across all speeds (p < 0.05). Limited effects of muscle damage were observed regarding swing-phase kinetics. In conclusion, walking biomechanics following muscle damage are affected differently at relatively higher walking speeds, especially with respect to knee and ankle joint motion. The importance of speed in evaluating walking biomechanics following muscle damage is highlighted.
In other words, different speeds, but especially punching up the tempo in a walk a wee bit seriously effected ankle joint ROM (it decreased) knee joint flexion (bigger), hip extension (leg going back) got smaller, pelvic tilt (more strain on the lower back) also increased, and just general tempo was also buggered up: participants were taking a wider stance while walking. 

In the Discussion section of the article, the authors speculate about what might be happening at say the hip or knee or ankle such that the gait changes in different parts of the gait cycle, and even what may be happening with pain messaging.

Just for context, here's a look at the walking gait cycle:

Main thing: the cycle has two phases: stance and swing. Swing phase is where the action is: toes are cleared; limbs move forward.

Some Observations by the Authors:
Less knee flexion in the swing phase was observed in slow speeds. The authors speculate that this is as a result of less desire to call upon the hamstrings to work to pull up the knee/clear the foot due to pain. At faster speeds though, the ankle goes wonky - destabilizing at the ankle. THe authors wonder if fear of falling from walking fast on a narrow treadmill is why this is happening. In other words, the knees look "normal" at faster speeds, but the ankles pay for it.

Also, hip flexion is shrunk as speed goes up: greater hip flexion means more involvement of the quads and they're sore: so compensation is more steps; tinier range of motion. Another compensation here is that to keep the stride length more or less up (tho compromised), without involving the hip flexors, the authors suggest a kind of psuedo hip extension by getting anterior pelvic tilt to compensate for missing hip flexion. Indeed, the authors note, there's a well observed pattern of positive correlation from other studies between reduced hip extension and anterior pelvic tilt. So a little bit of DOMS brings on a variety of gait pattern changes and systemic effects depending on speed.

It's just the Knee muscles? And that's screwing up Ankle Flexion, hip flexion and pelivic tilt?One of the things that really strikes me about this is that the only muscles worked into the DOMS state were the knee extensors and flexors (we talked about these when we discussed the ottoman pistol: extensors; flexors).  In other words, all these effects from giving one DOMS in the knees.

To induce the muscle damage and hence DOMS, the resaerchers have the participants do finely set up leg extensions from 100 degrees to 0 degrees (knee fully extended, getting the quads) and then knee flexions of 0 to 100 degrees (getting the hamstrings).  5 sets 15 reps each set; 3 min break btwn sets on an isokinetic dynamometer.  As hard as possible with the dyno set at 60o/s. (If you're really intrigued, here's a video of the cybex; if you'd like to learn about active dynomometry and overview is here).

From here, at different times after these exercises, a standard set of muscle damage / doms tests were run via bloodwork and other measures. They were really thorough (review of doms measuring here).

The researchers pre and post tested the participants using a treadmill set at different speeds, including letting participants choose their own comfortable walking speeds/transition speeds.

Pain changes everything?
Perhaps it's not novel at all to suggest that pain changes everything when it comes to movement.

I guess why this study is so striking to me is that it looked in a very controlled way at inducing and measuring a particular level of actual damage and correlated pain and muscular limitations to investigate specifically what pain does to problably our most basic movement pattern, walking. It focued on typical measures of lower body involvement in the gait cylce, and saw that especially when changing speed, gait mechanics change, but even when not changing speed, spatio-temporal movements changed: widened base of support, different tempo of gait. None of these changes is positive. More anterior pelvic tilt is not a happy compensation for reduced hip ROM as anyone with chronic low back pain may attest.

Speed of Adaptation/Compensation: It's Immediate. Look at how quickly the body begins to compensate to this single joint pain: Compensations are seen at the hip, pelvis ankle and the knees as well. They're different at different speeds. This study only looked at gait; it would be interesting to have seen shoulder and head involvement in these altered patterns as well.

What happens when we move from an acute pain bout to something more chronic, and those adaptations become more chronic too? Those adaptations are going to stick around and cause their own compensations.

Training at Speeds: High Payoff Future Proofing.
The authors conclude pretty much that pain impacts performance across gait at all speeds, but how particularly it effects mechanics depends on speeds.

One of the things wer're taught in z-health starting at R-Phase (overview of R here) is to practice mobility drills to "own" them at all speeds, and four speeds are spec'd from super slow to athletic. Pain is pain, but i wonder from this if practicing movement at different speeds, which means at different loads, too, would see one able to recover good form faster, better? Maybe keep more of that form?

We seem to see such recovery in folks who practice mobility work regularly, and who have strategies for understanding and working with the movement of their bodies.

Indeed, consider the authors' hypothesis that ankle flexion may be compromised post the muscle damaging exercise because there's a fear of being able to keep stable on a narrow track going at higher speeds, so we get weird dorsiflexion and gate.

This hypothesis reminds me of work that has been done with athletes to future proof them from ankle sprains by doing deliberate mobility work with them to improve balance and proprioception. This kind of loaded future proofing is a big part of z-health's i-phase work (follows r-phase): once the core mobility work is owned, start getting it into sport/life specific positions. An overview of i-phase: loading for the real is here.

Take Aways:
  • Pain changes movement, immediately, causing perterpations in range of motion and engagement of joints
  • Pain's particular changes are often speed dependent - from slower through to faster.
  • Better, praciticed mobility at various speeds, loads and ranges of motion strongly seems to help recovery of optimal motion and thus pain reduction (see related discussion on pain). 
  • Z-Health (overview) is a great way to learn and practice some of this movement self-awareness

Addeda - Personal Testimony; where to start: i tend to recommend z health for pain/performance because i've found it works for myself and for the folks i have the pleasure to coach.
Optimal place to start? with a zhealth coach / master trainer for a movement assessment and introduction to zhealth drills. If that assessment doesn't feel possible right now, dig in with R-phase for mobility drill learnin', or with the Essentials of Eliter Performance, if you'd like more of a workshop style theory + practice overview.  Tons of z discussions at the movement index on b2d.

By all means leave questions in the comments, below.

Tsatalas, T., Giakas, G., Spyropoulos, G., Paschalis, V., Nikolaidis, M., Tsaopoulos, D., Theodorou, A., Jamurtas, A., & Koutedakis, Y. (2010). The effects of muscle damage on walking biomechanics are speed-dependent European Journal of Applied Physiology, 110 (5), 977-988 DOI: 10.1007/s00421-010-1589-1

Ferguson SA, Marras WS, Burr DL, Davis KG, & Gupta P (2004). Differences in motor recruitment and resulting kinematics between low back pain patients and asymptomatic participants during lifting exertions. Clinical biomechanics (Bristol, Avon), 19 (10), 992-9 PMID: 15531048

Cools AM, Witvrouw EE, Declercq GA, Danneels LA, & Cambier DC (2003). Scapular muscle recruitment patterns: trapezius muscle latency with and without impingement symptoms. The American journal of sports medicine, 31 (4), 542-9 PMID: 12860542

Related Posts

No comments:


Related Posts with Thumbnails