17 Feb What does grip strength have to do with our bones?
Grip Strength, Bone Density, and the Pathway of Weight
Recent studies show that weaker grip strength is significantly correlated with lower bone density—particularly in the hips, lumbar spine, and wrist. At first glance, this seems intuitive for the wrist. But the hips? The lumbar spine? Why would the strength of your hand reflect the mineral density of bones far from your fingers?
I have a few theories.
In my Yoga for Vital Bones classes we’ll explore the logic of these findings through somatic exercises—practices that help us feel, not just think about, how force and weight travel through the body. But first, let’s unpack one developmental idea shared by one of my anatomy teachers, Amy Matthews, that might help frame the conversation.
From Center to Periphery: How We Learn to Move
There’s a widely accepted developmental principle: control of movement progresses proximally to distally (i.e. from the inside to the outside.)
When babies are born, they can grasp reflexively. Their fingers close around yours almost immediately. But that doesn’t mean they control their hands. Reflex is not volition.
Volitional control—the ability to choose and finely regulate movement—develops over time. And it develops from the center outward.
If circumstances support healthy motor development, an infant first gains control axially (with the spine): lifting the head, organizing the spine, stabilizing the pelvis. Then the shoulders and hips begin to differentiate. After that, elbows and knees. Then wrists and ankles. Finally, the hands and feet—and eventually the fine motor precision of the fingers.
Upper and lower limbs overlap in this progression, and often the upper limbs lead slightly. But the overall pattern holds: we develop control from the spine outward toward the periphery.
Proximal to distal.
But Mature Movement? That’s Another Story.
Here’s where it gets interesting.
Once volitional control is established, sophisticated movement may initiate distally.
This isn’t a moral claim—distal initiation isn’t “better.” And it doesn’t account for injury, context, emotional state, or habit. But mechanically speaking, initiating movement at the periphery often gives us the most refined calibration of effort.
Imagine reaching to turn a doorknob.
If you initiate from the shoulder, you might over-recruit. If you initiate from your center without sensing the object, you might use more force than necessary. But if your fingertips first make contact and assess—texture, resistance, weight—they can recruit only what is needed. If the fingers need help, they call in the forearm. If the forearm isn’t enough, the upper arm joins. The scapula orients. The spine responds.
The organization moves inward based on distal feedback.
This is efficient engagement with the environment.
And it suggests something profound: our hands may not just express strength. They may organize it. (This is where the fascia comes in, but that’s another conversation.)
The Pathway of Weight: Hands to Tail
Let’s talk about bones.
If we take as a premise that bones transmit weight and force, then there must be a structural pathway from our extremities to the spine.
Here’s one such pathway that Amy pointed out in a recent class—from the hand to the tail – it was an “ah ha!” moment for me:
- Ulnar hand (pinky finger side)
- Radial hand (thumb side)
- Radius & ulna (forearm)
- Humerus (upper arm)
- Glenoid fossa (arm socket)
- Lateral border of scapula (shoulder blade – click for visual aid…)
- Inferior angle of scapula (lower tip of shoulder blade)
- Medial border of scapula
- Spine of scapula
- Acromion process (where shoulder blade meets collarbone)
- Clavicle (collarbone)
- Sternum (breastbone)
- Ribs (wrapping from the front of body around to the spine)
- Vertebral bodies (note this is the front of the spinal column – click for visual)
- Sacrum (spine nestled into the pelvis)
- Coccyx (tailbone)
Notice something crucial: there is no direct bone-to-bone connection (via ligaments) between the shoulder blade and the ribs in the back. The shoulder girdle attaches to the axial skeleton (the spine and head) at only one true skeletal joint—the sternoclavicular joint at the front of the body where the sternum meets the clavicle (breastbone meets the collarbone.)
So if weight travels from the hand toward the spine, it must transition from back to front. It must move through the collarbone and sternum to reach the ribcage and then the spine. The ribs curve in the back and are actually connected to the vertebral bodies at the front of the spine! (Here’s a visual looking down to the first rib from above.)
That means grip is not just a local hand action. It is part of a full-body transmission system.
So Why Would Grip Strength Correlate With Hip and Lumbar Bone Density?
Here’s one possibility:
If bones adapt to the forces transmitted through them (as they do), then the integrity of distal engagement (e.g., through your hand) may influence how force is distributed proximally (i.e., through the spine.) If someone habitually under-recruits distally—if the hands do not effectively engage and transmit load—the entire pathway of weight may be diminished.
Less transmitted load means less mechanical stimulus.
And bones require mechanical stimulus to maintain density.
The wrist is obvious. But the lumbar spine and hips are major load-bearing hubs. If force from the upper limbs is efficiently transmitted through the clavicle, sternum, ribs, and spine, the axial skeleton experiences meaningful load. If that transmission is muted, interrupted, or chronically bypassed, the axial system may experience less varied, multidirectional stimulus.
Grip strength, then, might be a proxy—not merely for forearm muscle mass—but for how effectively a person organizes distal-to-proximal load.
It might reflect the vitality of the entire pathway.
It’s Not a One-Way Street
Earlier I mentioned that movement development proceeds from center to periphery. But mature organization can travel both ways.
Think of it as a trail.
You can start at the spine and find your way out.
You can start at the fingertips and find your way in.
In our somatic explorations, we’ll trace both directions. From breath and spine outward. From fingertips inward.
Because if bones transmit weight, and if the pathway exists, then improving how we sense and use that pathway may influence not just strength—but density, support, and resilience.
Grip strength may be telling us something deeper.
Not just about the hand.
But about the relationship between our extremities and our center.
In Yoga for Our Vital Bones we practice feeling that relationship directly.
References:
Kamiya K, Kajita E, Tachiki T et al (2019) Association between hand-grip strength and site-specific risks of major osteoporotic fracture: results from the Japanese Population-based Osteoporosis Cohort Study. Maturitas 130:13–20. https://doi-org.libproxy2.usc.edu/10.1016/j.maturitas.2019.09.008
Zhu Y, Chi K, Wang J. Mendelian randomization study on association between grip strength and BMD in different age groups. Journal of bone and mineral metabolism. 2024;42(5):564-581. doi:10.1007/s00774-024-01519-1
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