Effects of Running on the Spine
Running has predominantly beneficial effects on spinal bone health by reducing age-related bone loss, while the mechanical loading during running causes temporary, reversible spinal compression that does not correlate with low back pain development.
Bone Health Benefits
Running provides significant protective effects against spinal bone loss, particularly in the lumbar spine. Regular running reduces age-related bone mineral density (BMD) decline in both men and women over 50 years of age 1. A 5-year longitudinal study demonstrated that runners maintained significantly greater lumbar BMD compared to sedentary controls, with a highly significant correlation between time spent running (minutes per week) and preservation of lumbar bone density 1.
The osteogenic benefit is dose-dependent: Changes in BMD were positively correlated with changes in running volume, and runners who substantially decreased their running habits experienced the most pronounced bone loss 1.
However, running alone may not provide sufficient impact forces for optimal bone strengthening 2. Running does not subject the body to high enough impacts (greater than four times body weight) to produce maximal osteogenic effects 2.
Combining running with high-impact plyometric training and resistance exercise produces superior bone benefits, particularly for lumbar spine and femoral neck BMD 2. Programs incorporating multiple exercise types or resistance training showed standardized effects of 0.26 for lumbar spine BMD 2.
Mechanical Loading and Spinal Compression
Running causes temporary spinal shrinkage (compression) that is speed-dependent but does not indicate pathology. During 30 minutes of running, spinal shrinkage ranges from 3.37 mm at 70% marathon pace to 7.69 mm at 100% pace 3.
Spinal compression is greatest during the first 15 minutes of running (3.26 mm) compared to the second 15 minutes (2.12 mm), suggesting an initial loading phase followed by adaptation 3.
Critically, this spinal shrinkage shows no correlation with low back pain development 3. Runners with chronic low back pain demonstrated identical spinal compression responses to pain-free runners across all running speeds 3.
The impact load generated during heel strike travels up the lower extremity kinetic chain and converges on the lumbar spine, but is normally minimized through biomechanical actions of joints and supporting soft tissues 4.
Biomechanical Considerations
Proper running biomechanics are essential to prevent spinal stress, with trunk position being particularly important. Poor running technique, especially excessive forward lean, requires compensatory contraction of back extensors that can produce high intersegmental forces on the discs 5.
An upright posture with minimal forward lean is recommended to reduce excessive back extensor activation 5.
Shock absorption should be optimized by allowing proper "giving" at the ankle, knee, and hip joints during foot strike 5.
Running on softer surfaces (tracks rather than concrete), using high-quality cushioned shoes, and avoiding hills during symptomatic periods reduces spinal loading 5.
Trunk stabilization ability is crucial: Individuals who previously experienced pain while jogging may be able to run pain-free after learning to maintain a neutral, stabilized spine position 5.
Postural Adaptations
Running induces specific postural changes that affect spinal mechanics. Triathletes adopt a more forward-leaning posture during running after cycling, which affects running efficiency 2. This trunk gradient change may result from modifications in abdominal and lumbar muscle contraction induced by altered sensory feedback 2.
- Neurosensory adaptation occurs with running, as proprioceptive feedback persists for a short period after cessation of activity, potentially causing postural compensation to be temporarily out of phase with actual feedback 2.
Clinical Implications for Spinal Pathology
Running is generally protective rather than harmful for the spine, but specific conditions require caution. While no association exists between running mileage and osteoarthritis development 5, running-related spinal injuries, though uncommon, can be debilitating 4.
Dysfunction anywhere in the lower extremity kinetic chain can create cascading mechanical adaptations throughout the spinal axis 4. Similarly, spinal dysfunction can create peripheral joint adaptations 4.
Red flag screening is essential: Recreational runners can present with low back pain as the sole symptom of serious underlying conditions such as thoracolumbar fractures 6.
For individuals with existing low back problems, running may be appropriate if proper trunk stabilization is achieved and biomechanics are optimized 5. Alternative activities like backstroke swimming, brisk walking, stair climbing, or cross-country ski machines provide aerobic conditioning with less spinal impact 5.
Rehabilitation Context
After tibial bone stress injuries, running progression must be carefully managed to allow spinal adaptation. Exercises should be performed on alternate days, as bone cells regain 98% of mechanosensitivity after 24 hours of rest 7.