Perhaps we need to change how we are are rehabbing X (insert your favorite weight bearing joint)

image credit: https://en.wikipedia.org/wiki/StrongBoard_balance

We have recently run across some research that has changed the way we look at some of the rehab we do, especially proprioceptive rehab. Perhaps it will do the same for you.

Traditionally, we present increasing balance requirements to the weight bearing structure by changing one or more of the three parameters that keep us upright in the gravitational plane: vision, the proprioceptive system (which include the muscles, joints and ligaments) and the vestibular system (the utricle, saccule and semicircular canals). We have discussed them extensively in multiple articles here on the blog. We generally would make the rehab task more difficult by removing a stimulus (closing your eyes, having someone stand on foam) or challenging (standing on one leg, putting someone on a wobble board, BOSU, extending the head, etc) the to make it more durable and "educated". More difficult task + better balance = more stable joint and better outcomes. 

The importaat thing is to think about how much of each system is apportioned; we often (wrongly) assume it is pretty equally divided between the three. It turns out, that it really depends on the surface you are standing on and the circumstances.

On flat planar surfaces, the division of labor looks something like this:

• proprioceptive system 70%
• vestibular system 20%
• visual system 10 %

On uneven or unstable surfaces (like a BOSU, dynadisc, foam, Swiss ball, etc), it looks like this:

• vestibular system 70%
• visual system 20%
• proprioceptive system 10%

So, if we are rehabbing an ankle, it would make the most sense to do most of the rehab (and additional challenges) on a flat planar surface, perhaps incorporating things like forward, backward and side lean, toe and heel work and closed chain strengthening. WE could also close the eyes to make them more dependent on the proprio system, or extend the head 60 degrees to dampen the influence the lateral semicircular canals. We can put them on a BOSU or unstable surface but we need to remember that in that case, we will be rehabbing the vestibular system AND PERHAPS teaching THAT SYSTEM to compensate more, than the "broken" system. Yes, they get better BUT we are not fixing the system that is injured. 

You could make the argument, that your athletes/clients run/walk/exercise on uneven surfaces and use their vestibular system more.Maybe so, but is the actual injury to the vestibular system or to the musculoskeletal one?

Armed with this information, try and think of the system that is compromised and focus your efforts on that system, rather than the other two. Yes, people have vestibular dysfunction and refractive errors and need therapy, exercises and/or corrective lenses, but many of us are not vestibular or opticokinetic therapists (kudos to those of you who are!)

Peterka RJ, Statler KD, Wrisley DM, Horak FB. Postural Compensation for Unilateral Vestibular Loss. Frontiers in Neurology. 2011;2:57. doi:10.3389/fneur.2011.00057.

Horak FB. Postural Compensation for Vestibular Loss. Restorative neurology and neuroscience. 2010;28(1):57-68. doi:10.3233/RNN-2010-0515.

We hope you are standing up while you read this….

A newborn’s brain is only about one-quarter the size of an adult’s. It grows to about 80 percent of adult size by three years of age and 90 percent by age five (see above). This growth is largely due to changes in individual neurons and their connections, or synapses.

The truth is, most of our brain cells are formed at birth, In fact, we actually have MORE neurons BEFORE we are born. It is the formation of synapses, or connections between neurons, that actually accounts for the size change (see 1st picture above). This is largely shaped by experience and interaction with the environment.

Do you think children’s brains are less active than adults? Think again, your 3 year old’s brain is twice as active as yours! It isn’t until later in life that you actually start dialing back on some of those connections and those pathways degenerate or fade away…a process scientists call “pruning”.

How does this apply to gait? Gait depends on proprioception, or body position awareness. Your brain needs to know where your foot is, what it is standing on and so on. Proprioception, as we have discussed in other posts, is subserved by muscle and joint receptors called mechanoreceptors (muscle spindles, golgi tendon organs and type 1-4 joint mechanoreceptors to be exact). This information is fed to 2 main areas of the brain: the cerebral cortex and the cerebellum. These 2 parts of the central nervous system are interconnected on many levels.

The cerebellum is intimately associated with learning. Try this experiment. you will need a tape recorder (guess we are showing our ages, digital recorder), a timer and a moderately difficult book.

Sit down and pick a section of the book to read. start the recorder and timer and read aloud for 2 minutes. Stop reading, stop the recorder and stop the timer.

Stand up, somewhere you won’t get hurt if you fall. Stand on 1 leg (or if available, stand on a BOSU or rocker board). Open the book to a different spot. Start the timer, the recorder and start reading again for 2 minutes.

Sit back down and grab a snack. Listen to the 2 recordings and pay attention to the way you sound when you were reading, the speed, fluency and flow of words. Now think about recall. Which passage do you remember better?

The brain works best at multitasking and balance and coordination activities intimately affect learning. Having children sit in a class room and remain stationary and listen to a lecture is not the best way to learn. We always tel our students to get up and move around…

This article looks at this relationship in a slightly different way.

We hope you are still standing : )

 Lopes VP, Rodrigues LP, Maia JA, Malina RM.Motor coordination as predictor of physical activity in childhood. Scand J Med Sci Sports. 2011 Oct;21(5):663-9. doi: 10.1111/j.1600-0838.2009.01027.x. Epub 2010 Mar 11

Abstract

This study considers relationships among motor coordination (MC), physical fitness (PF) and physical activity (PA) in children followed longitudinally from 6 to 10 years. It is hypothesized that MC is a significant and primary predictor of PA in children. Subjects were 142 girls and 143 boys. Height, weight and skinfolds; PA (Godin-Shephard questionnaire); MC (Körperkoordination Test für Kinder); and PF (five fitness items) were measured. Hierarchical linear modeling with MC and PF as predictors of PA was used. The retained model indicated that PA at baseline differed significantly between boys (48.3 MET/week) and girls (40.0 MET/week). The interaction of MC and 1 mile run/walk had a positive influence on level of PA. The general trend for a decrease in PA level across years was attenuated or amplified depending on initial level of MC. The estimated rate of decline in PA was negligible for children with higher levels of MC at 6 years, but was augmented by 2.58 and 2.47 units each year, respectively, for children with low and average levels of initial MC. In conclusion MC is an important predictor of PA in children 6-10 years of age.

GOT ENDURANCE?

We all realize the importance of endurance work, especially when it comes to core work. If we had a dollar for every patient that lacked lower back extensor endurance that had a gait problem......

In this video, Dr Ivo demonstrates his adaptation of Dr Eric Goodman's "Founders" sequence, along with some clinical commentary. Try this on yourself or with your patients/clients today. It's easy and effective.

More effective stretching, Part 2

Last week we looked at one (of many) methods to make stretching more effective, utilizing a neurological reflex called “reciprocal inhibition” If you missed that one, or need a review, click here. 

Another way to get muscles to the end range of motion is to utilize a technique called “post isometric relaxation”. Notice I did not say to lengthen the muscle; to actually add sarcomeres to a muscle you would need to use a different technique. Click here to read that post.

Contracting a muscle before stretching is believed to take advantage of a post isomteric inhibition (sometimes called autogenic inhibition), where the muscle is temporarily inhibited from contracting for a period immediately following a isometric contraction. This has been popularized by the PNF stretching techniques, such as “contract hold” or “contract relax” . EMG studies do  jot seem to support this and actually show muscle activation remains the same (1, 2) or increased after contraction (3-6). Perhaps it is due to an increased stretch tolerance (7,8). 

The technique was 1st described by Mitchell, Morgan and Pruzzo in 1979 (9). These gents felt it was important to utilize a maximal contraction (using 75-100% of contractile force) to get to have the effect. It was later shown by Feland and Marin (10) that a more minimal, submaximal contraction of 20-60% accomplished the same thing.  Lewit felt that a less forceful contraction offers the same results, and combined respiratory assists (inspiration facilitates contraction, expiration facilitates relaxation) with this technique (11). Interestingly, there are bilateral increases in range of motion with this type of stretching, indicating a cross over effect (12). Regardless of the mechanism, the phenomenon happens and we can take advantage of it. 

This is how you do it: 

• Bring the muscle to its end range (maximum length) without stretching, taking up the slack. This should be painless, as this will elicit a different neurological reflex that may actually increase muscle tone. 
• resist with a minimal isometric contraction (20-60%) and hold for 10 seconds.  You can inspire to enhance the effect.
• relax and exhale slowly. It is important to wait and feel the relaxation. Stretch through the entire period of the relaxation. You should feel a lengthening of the  muscle.
• repeat this 3-5 times

This technique can also be used with the force of gravity offering isometric resistance. In a hamstring stretch, you could lean forward while maintaining the lumbar lordosis and allowing the weight of the upper body to provide the stretch. 

Wasn’t that easy? Now you have another tool in your toolbox for yourself or your clients.

The Gait Guys. Giving you useful information and explanations in each and every post.

1. Magnusson SP, Simonsen EB, Aagaard P, Sorensen H, Kjaer M. A mechanism for altered flexibility in human skeletal muscle. J Physiol. Nov 15 1996;497 (Pt 1):291–298
2. Cornelius WL. Stretch evoked EMG activity by isometric coontraction and submaximal concentric contraction. Athletic Training. 1983;18:106–109
3. Condon SM, Hutton RS. Soleus muscle electromyographic activity and ankle dorsiflexion range of motion during four stretching procedures. Phys Ther. Jan 1987;67(1):24–30 
4. Mitchell UH, Myrer JW, Hopkins JT, Hunter I, Feland JB, Hilton SC. Neurophysiological reflex mechanisms’ lack of contribution to the success of PNF stretches. J Sport Rehabil. 2009;18:343–357 
5. Youdas JW, Haeflinger KM, Kreun MK, Holloway AM, Kramer CM, Hollman JH. The efficacy of two modified proprioceptive neuromuscular facilitation stretching techniques in subjects with reduced hamstring muscle length. Physiother Theory Pract. May 2010;26(4):240–250 
6. Osternig LR, Robertson R, Troxel R, Hansen P. Muscle activation during proprioceptive neuromuscular facilitation (PNF) stretching techniques. American journal of physical medicine. Oct 1987;66(5):298–307
7. Mahieu NN, Cools A, De Wilde B, Boon M, Witvrouw E. Effect of proprioceptive neuromuscular facilitation stretching on the plantar flexor muscle-tendon tissue properties. Scandinavian journal of medicine & science in sports. Aug 2009;19(4):553–560 
8. Mitchell UH, Myrer JW, Hopkins JT, Hunter I, Feland JB, Hilton SC. Acute stretch perception alteration contributes to the success of the PNF “contract-relax” stretch. J Sport Rehabil. May 2007;16(2):85–92
9. Mitchell F Jr., Moran PS, Pruzzo NA: An Evaluation of Osteopathic Muscle Energy Procedures. Pruzzo, Valley Park, 1979.  
10. Feland JB, Marin HN. Effect of submaximal contraction intensity in contract-relax proprioceptive neuromuscular facilitation stretching. Br J Sports Med. Aug 2004;38(4):E18.
11. Lewit K: Postisometric relaxation in combination with other methods of muscular facilitation and inhibition. Man Med, 1986, 2:101-104.
12. Markos PD. Ipsilateral and contralateral effects of proprioceptive neuromuscular facilitation techniques on hip motion and electromyographic activity. Phys Ther. Nov 1979;59(11):1366–1373