The Movement You Need is on Your Shoulder
I really enjoy making music, and when I had children, I encouraged them to play from an early age. I strewed my house with instruments of every ilk, and placed little working miniatures of my favorites in their hands by age two. Then I noticed some troubling changes in their skeletal alignment. Of course, by the time I realized I was negatively influencing their physical development, they'd both realized they really like music.
Oops.
I’d never have thought that playing an instrument for fun could be anything but beneficial, yet progressive changes in skeletal alignment told a different story.
The acquisition of specialized, modern skills-sets interfere with the reflex-driven movement patterns so essential to health and longevity. That’s a fact [1]. It’s bad enough that it engenders degenerative disease in the adult population, but let's face it, the habits begin in childhood. Traditionally kids didn’t experience adult discomforts, even though they engaged in the modern movement patterns—it was offset by hours gallivanting outdoors, walking everywhere. Unfortunately, today's youth are faced with disappearing opportunities for the type of movement that delays the onset of pain, Type 2 Diabetes, and Osteoporosis.
So, what's so problematic about instruments?
Instruments all have a couple of things in common. If they're played by humans, they're played in front of the body, require the use of arms, and many, many hours of practice. My kids play string instruments, but it holds true for ANY instrument, woodwinds, brass, percussion, piano, guitar--it doesn't matter, except that the higher you have to raise your arms, the heavier your instrument, and the less symmetrical your movements, the more it hurts.
ANY type of sustained immobilization of a joint over time results in a successive decrease in that joint’s range of motion. The body will have to compensate for this by changing it’s natural alignment and gaining inappropriately high levels of mobility in surrounding joints. A cascade of tissue damage ensues, including the build-up of cellular waste as lymph flow becomes impaired.
The position below creates a situation in which the muscles of the back become long and weak, the muscles of the chest and upper arms become short and tense, and the intervertebral discs of the neck become compressed and sore. The trapezius muscles, which should be a part of the back, end up looking like visible extensions of the neck.
The shoulder girdle ends up shaped more like a C than a straight line, and the head is displaced forward. Here is an illustration looking down upon the figure from above. The oval is a head. The line represents shoulders. I labeled one normal, and one natural, which might be a little confusing. Let me explain.
Have you ever asked your doctor about a problem only to be told, “It’s perfectly normal”? Maybe, despite this reassurance, your worry persists, because if the malady was truly normal, you wouldn’t have needed to ask about it. A better word choice might have been “common.” It is extremely common, so common, in fact, that it can be incorrectly termed normal. This type of semantic shift is inevitable, when the health of an entire population is deteriorating. 
The figure on the left is the shoulder girdle arrangement born from hours of holding the arms out in front of the body, engaging in unnatural motor patterns that lay the foundation for Carpel Tunnel Syndrome, Shoulder Impingement, Cervical Spine Degeneration, and the like. The figure on the right is the way a shoulder girdle should and would be arranged, if we humans still used our arms as biologically designed. You can try and fake the natural alignment illustration if you want to, but don't be fooled. The alignment marker needed to objectively evaluate your shoulder girdle health is scapular (shoulder blade) position—they need to be protracted, that is, as far apart from each other as necessary for the blade border closest to your spine to become level with the musclulature of the back.
Take the test. Give yourself a big bear hug. Your scapulae are protracted. Next let your arms hang down at your sides, but KEEP YOUR SCAPULAE PROTRACTED. Are you normal, or natural? In this position, can you get your ear to stack vertically above your shoulder, or is your head out in front? Are your arms hanging forward, with your wrists facing frontward, somewhat like a gorilla?
I'll admit, (and this is probably the only instance for which it's true) I'm normal. Little kids would be natural, if their lives were less “enriched” with all that education, culture and...stuff.
I used 3 years worth of family photos to find evidence of the physiological interference playing the violin caused my daughter. For you or your kid it could be athletics, art, riding bikes, playing video games, sitting down to study, eat or watch TV —I know, I know. All normal activities, right? But the general posture is all the same.
The picture on the left is my daughter at age 4. Her shoulder girdle has a wide, straight arrangement, there are no visible trapezius muscles, and her ears stack vertically above her shoulders. The picture on the right is the same child 18 months later. Her shoulders are characterized by a steep slope, have migrated forward, and she can no longer stack her head vertically. To compensate, she is nodding her chin up slightly. Here the painful habit of cervical extension begins. This positioning increases her risk for stroke later in life.
The solution is to build upper body strength, of a kind in which the muscles are being strengthened and lengthened concurrently. We need an activity that forces muscles to perform expansively, pulling away from the center of the body to allow the shoulder girdle to settle into a wide, natural, pain-free alignment. I am talking about functional upper body strength and endurance. It's not about how big ones guns look, but how they work. Let's take a moment to clear up any confusion. Has anyone been thinking,
"What? Big traps aren't good?"
Um, no. NO, NO, NO. The trapezius muscles have this constant upward tension, that’s supposed to be balanced by the latissimus dorsi, those large, downward pulling muscles.
If you don't have equally strong lats, then you have no right to those visible traps. Your brain might think I'm wrong, but your stiff neck or tingling hands are begging you to listen to me. You can check the strength of your lats by how well you would perform any of these simple skills mastered by the man below, Yuuji Urushihara, a supreme example of functional upper body strength.
As you watch him do his thing, notice how stable his shoulders are. Yuuji's scapulae do not move, he uses his lats to stay in control, and his trapezius muscles are right where they belong. ON HIS BACK. This fellow has arms, hands and shoulders that are useful with the kind of musculature we tend to characterize as wiry...see the difference?
Taking Yuuji's example to heart, my family began functional upper body strength training by hanging on a pull-up bar and progressed through rock walls and tree climbing. The children, outstripped their mom, and moved on to monkey bars, and bouldering. When their hand and latissimus dorsi strength increased enough, we found good old-fashioned Tarzan of the Apes vine skills were hands down, the quickest and most effective way to make the shoulder girdle right. Rope climbing forces the shoulder to move in its correct channel.
Here are the results 6 months later. She still has visible traps, but their bulk has decreased. Her shoulders have widened outwards, and she is once again able to stack her head vertically. She has lowered her chin, and is no longer in cervical extension. The cool thing about climbing, is that a parent can encourage it without ever having to nag. Just take a walk to the park and try the monkey bars yourself. I guarantee your kids will want to show you how it's done. Hang a rope in the house or in a tree in the back yard and your kids will have a fighting chance for life-long upper body health.