#leg swing

[autistickeely]

I love my new gadget!! 😍 It’s an under desk leg swing which is amazing for stimming and also calms me down when I’m feeling stressed.

[findingnaturalcures]

THIS EXERCISE IS EASY AND SLIMS LEGS! LEG SWING EXERCISE #findingnaturalcures DON'T FORGET: Before doing the exercise, march in place for at least 2 min. to warm up the muscles.

HOW IS THE EXERCISE DONE? 1- Grab the back of the chair and swing your leg. 2- Put your other hand to your waist. 3- Bring your leg forward without touching the ground. 4- Repeat the exercise 10 times for one set. 5- Do the exercise with the other leg. 6- Do 3 sets for both legs. Try to do the exercise everyday and you will see the results in just 15 days. BENEFITS: 1- Burns the fat in inner thighs. 2- Strengthens the legs. 3- Works the thigh muscles and lifts the butt. 4- Helps to improve balance. 5- Regulates blood circulation.

[thegaitguys]

Coordination of leg swing, thorax rotations, and pelvis rotations during gait: The organisation of total body angular momentum

"In walking faster than 3 km/h, transverse pelvic rotation lengthens the step (“pelvic step”). The shift in pelvis–thorax coordination from in-phase to out of phase with increasing velocity was found to depend on the pelvis beginning to move in-phase with the femur, while the thorax continued to counter rotate with respect to the femur. "

We are always trying to bring greater understanding to this group at TGG regarding gait mechanics. One must understand the implications of rotational work, and anti-rotational work on the phasic and antiphasic nature of the thorax and the pelvis. We have talked about becoming more phasic when there is spine pain. With today's study, we delve just al little deeper, particularly noting how the pelvis and the femur moving together first, before that is offset by the antiphasic nature of the thorax at higher speeds of gait. This article uses the terms in phase and out of phase. We have learned over time that those terms to relate more so the description of how the limbs are, or are not, pairing up when a couple is walking together. None the less, the reader here should understand how they are referring to out of phase as antiphasic.

http://www.sciencedirect.com/…/article/pii/S096663620700135X

[thegaitguys]

Whole-body coordination patterns may become partitioned in particular ways as a function of task requirements

Just some more thoughts for those who insist on coaching arm swing changes.

"Whole-body coordination patterns may become partitioned in particular ways as a function of task requirements.”

Toddlers actively reorganize their whole body coordination to maintain walking stability while carrying an object. Hsu WH1, Miranda DL2, Chistolini TL3, Goldfield EC4. Gait Posture. 2016 Oct;50:75-81

Today we seem to be going back to dual-tasking again, in this case utilizing the arms as balance assistance devices, amongst their other functions. However, we all know that walking with a hand in a pocket, or carrying something alters our ability to maximize their ballast-like function. Balanced walking involves freely swinging the limbs in pendullar motion. Changes in arm swing will change gait economy and efficiency. We have all run with a water bottle or bag/briefcase and know how that changes the symmetry and fluidity of our gait.

Today's research piece discusses toddlers and their function as they carry objects. "children immediately begin to carry objects as soon as they can walk. One possibility for this early skill development is that whole body coordination during walking may be re-organized into loosely coupled collections of body parts, allowing children to use their arms to perform one function, while the legs perform another. Therefore, this study examines: 1) how carrying an object affects the coordination of the arms and legs during walking, and 2) if carrying an object influences stride length and width." -Hsu et al.In this study of 10 toddlers with 3-12 months of walking experience were recruited to walk barefoot while carrying or not carrying a small toy. "Stride length, width, speed, and continuous relative phase (CRP) of the hips and of the shoulders were compared between carrying conditions. While both arms and legs demonstrated destabilization and stabilization throughout the gait cycle, the arms showed a reduction in intra-subject coordination variability in response to carrying an object. Carrying an object may modify the function of the arms from swinging for balance to maintaining hold of an object. The observed period-dependent changes of the inter-limb coordination of the hips and of the shoulders also support this interpretation. Overall, these findings support the view that whole-body coordination patterns may become partitioned in particular ways as a function of task requirements." -Hsu et al.

So once again we will say it, if you are coaching the arm swing YOU want, because you do not like what you see in your client, or if you think you are helping your client get more out of their body in terms of speed, power, efficiency or anything of the sort, know that there is a higher, smarter program running the show. And that program in the client’s CNS is smarter than you when it comes to what they need for whole-body coordination pattern generation.

[thegaitguys]

Your center of mass in relation to foot strike position.

For those arm swing/pulsers/ COM and head over foot folks consider some more research below. Let the CNS drive the show, it is what it is there for . . . The leg motor patterns are dominant, the arms are passive and "shape" and influence the leg swing as a balance and ballast effect. As we discuss in an upcoming podcast, to cross the arms in a pumping motion across the midline of the body means one has to have compromised scapular mechanics (mostly protraction) to afford that much humeral adduction. This means we are forcing thoracic rotation as well. This means we are reversing what we know is more true, that "arm motion is driven passively by rotation of the thorax (Pontzer et al., 2009), an idea which is supported by shoulder muscle EMG data" (and not thoracic rotation by arm swing). Why would we try to create more unnatural axial spin through the spine when we are actually trying to move forward in the sagittal plane? Why would we try to force more rotation through the spine when the function of the thoracopelvic canister (ie. the core) is to stabilize rotational /angluar momentum? Hmmmm, things to ponder.

"Previous modelling studies have clearly shown that motion of the arms effectively counterbalances the angular momentum of the lower extremities during running (Hamner & Delp, 2013; Hamner et al., 2010). It has further been suggested that arm motion is driven passively by rotation of the thorax (Pontzer et al., 2009), an idea which is supported by shoulder muscle EMG data, consistent with the shoulders as spring-like linkages (Ballesteros, Buchthal, & Rosenfalck, 1965). Our data are con- sistent with this idea, showing motion of the thorax to be in the opposite direction to that of the swinging leg. Pontzer et al. (2009) also suggested that motion of the thorax is driven passively by motion of the pelvis. However, our data shows that the thorax reaches its peak angular velocity earlier than the pelvis, indicating that thorax motion is not completely passively driven by pelvic movements."

-S.J. Preece et al. / Human Movement Science 45 (2016) 110–118

[thegaitguys]

Dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans

. . . dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans This suggests that arm swing is, to a notable degree, subservient to leg swing.

Research thus far has strongly suggested two pieces to arm swing, a passive and an active swing component. Without muscle activity, passive swing amplitude and relative phase decrease significantly. As phase decreases, it is referred to as in-phase swing pattern of the arms. The Goudriaan et al paper referenced below concluded that "muscle activity is needed to increase arm swing amplitude and modify relative phase during human walking to obtain an out-phase movement relative to the legs." But it is more complicated that this . . . .

Research continues to suggest that interlimb coordination is achieved at the brainstem and cortical level, which this study suggests as to why we can dual task and walk with something in our hands, carry objects and even walk and run with said objects and changes in our gait . . . . because, the program is running off a top down neurologic mediated process with predictable, economically CPGs(central pattern generator) in place. "The coordination of arm and leg movements takes the form of an in-phase relationship between diagonal limbs [64]. The dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans as well. For example, Sakamoto et al. [65] showed that during combined arm and leg cycling, the cadence of the arms was significantly altered when leg cycling cadence was changed. The opposite, however, was not true, i.e. the arms did not affect the leg cadence."-Preece et al.

Human Movement Science 45 (2016) 110–118 The coordinated movement of the spine and pelvis during running Stephen J. Preece, Duncan Mason, Christopher Bramah School of Health Sciences, University of Salford, Salford, Manchester M6 6PU, United Kingdom

Gait Posture. 2014 Jun;40(2):321-6. doi: 10.1016/j.gaitpost.2014.04.204. Epub 2014 May 6. Arm swing in human walking: what is their drive? Goudriaan M1, Jonkers I2, van Dieen JH3, Bruijn SM4.

[thegaitguys]

Central Pattern Generators (CPGs) and gait / locomotion. Do the arms and legs talk to eachother ?

On the topic of central pattern generators (CPGs) and gait / locomotion "If quadrupedal coordination is deeply embedded in the human nervous system then one might expect this to be revealed in conditions when there is a conflict between voluntary arm movements and walking. For example, Muzii et al. [44] combined a walking and a clapping task at preferred rates. Hand clapping was found to be tightly coupled to heel strike. When instructed to walk and clap at different rates (e.g. walk normally but clap faster) the subjects were not able to perform this task, implying that the walking rhythm dominated the coordination. Hence coupling is fairly robust, a finding that was confirmed by the observation that the typical 1:1 diagonal coordination during gait is maintained even when either one of the limbs involved is loaded with an extra 2 kg." - P. Meyns et al. / Gait & Posture 38 (2013) 555–562

We have discussed this same thing during our "dual tasking" blog posts. These things can be learned and modified with attentive training, but is it strongly suggested that the underlying CPG patterns are fairly robust.  This is not to say that leg swing is the king, that it runs the show, but it seems dominant. And as the Meyns paper reviews, there is an influence from the upper limbs in terms of enhancing and shaping the overall movement and coordination of all 4 limbs.

And as the Meyns paper states, "although the connections go both ways, it is clear in the to date animal models studied, that "the caudorostral connections seem to be the most powerful ones." Meaning, the pelvis and lower limb motor patterns and pattern generators seem to dominate over the upper limbs and upper pattern generator centers. "The dominance of the lumbosacral girdle over the cervicothoracic is probably preserved in humans as well. For example, Sakamoto et al. [65] showed that during combined arm and leg cycling, the cadence of the arms was significantly altered when leg cycling cadence was changed. The opposite, however, was not true, i.e. the arms did not affect the leg cadence." Meyns et al. And, "the authors concluded that ‘‘the neural signal induced by the upper limb movements contributes not merely to enhance, but to shape the lower limb locomotive motor output, possibly through interlimb neural pathways’’.-Myens et al.

The how and why of arm swing during human walking Pieter Meyns a,1, Sjoerd M. Bruijn a,b,1, Jacques Duysens a,c,* P. Meyns et al. / Gait & Posture 38 (2013) 555–562

[thegaitguys]

Arm Swing and dynamic stability of the system.

We have discussed the arm swing issue so many times over the years that we have lost count. By many sources, arm swing is a product of lower limb action and a product of the effective, or ineffective, relationship between the shoulder "girdle" (maybe thoracic rotation component) and the pelvic girdle (lumbopelvic rhythm) during gait.  This is the concept of phasic and anti-phasic limb swing. If you want to dive into that, and you should if you are unfamiliar with the concept, you can look it up on our blog using the search box.  We are not to forget that the arms, and thus arm swing, is a major factor in maintaining balance. We have used the term "ballast" many times to describe the effects of arm swing, rotation, abduction, circumduction etc on assisting balance maintenance of the body during various locomotion strategies. These are largely subconscious actions, hence why we agree with the research suggesting that arm swing is secondary, compensatory, and takes its queues off of the activity of the lower limb motor actions. In essence, arm swing variants are necessary compensations to assist in maintaining things like balance, center of pressure, equilibrium and the like. 

In this recent 2017 study, we have another suggesting arm swings function in assisting, even improving, dynamic stability. We are reminded of MdGill's suggestion, and the concepts of phasic and antiphasic torso-pelvis counter rotational movements, of how spinal loads can be affected by changes or differences in arm position.  Even arm position changes in sitting and standing can alter spinal loads, so during movement it is a virtual guarantee. 

This study looked at "how arm swing could influence the lumbar spine and hip joint forces and motions during walking." In this study, the researchers had each subject perform walking with different arm swing amplitudes and arm positions. Here is a comment from the researchers on what they found, it is pretty much what we have been writing about for several years based off of other research"

"The range of motion of the thorax with respect to the pelvis and of the pelvis with respect to the ground in the transversal plane were significantly associated with arm position and swing amplitude during gait. The hip external-internal rotation range of motion statistically varied only for non-dominant limb. Unlike hip joint reaction forces, predicted peak spinal loads at T12-L1 and L5-S1 showed significant differences at approximately the time of contralateral toe off and contralateral heel strike." Thus, we find yet another study confirming what many will say is obvious, that being arm position and movements have notable effects on whole body kinetics and spinal loads. This study suggested that arm variations did not have an effect on spinal loads during walking. We find this curious; it is something we will be looking into, and pondering. We hope you do as well. Effect of arm swinging on lumbar spine and hip joint forces

Lorenza Angelini et al. Journal of Biomechanics, Sept 2017 http://www.sciencedirect.com/science/article/pii/S0021929017304670