World Physical Therapy Day: Sleep Posture and Pillow Fit at Every Age

Last updated: October 2026

Sleep fits into a physical therapy plan at any age because it is the longest static posture of the day, and pillow height measurably changes neck alignment and muscle activity during it, in studies of young adults (Kim et al., 2015; Jiao et al., 2025). Physical therapists help people stay active and moving through every stage of life. On World Physical Therapy Day, September 8, the first half of this article covers what the pillow changes, and the second half covers how a fitted pillow joins the plan.

Key takeaways

In a prospective cohort of 1,955 healthcare workers followed for one year, moderate and poor sleep at baseline were associated with increased odds of developing low back pain (Vinstrup et al., 2020).
In a pilot study of 15 adults using surface EMG, the pillow height matching shoulder width produced the lowest neck and shoulder muscle activity during side sleeping (Jiao et al., 2025).
Pillowise sleep specialists take three measurements, shoulder width, neck circumference and neck length, and with sleeping position and bed type an algorithm identifies the best-fitting pillow from seven sizes.

Why does sleep matter to a physical therapy plan?

Pain and sleep travel together. In a cross-sectional study of 3,593 Danish hospital workers, a high pain score raised the risk ratio for poor sleep to 1.48, and 57 percent reported poor sleep overall (Vinstrup et al., 2018).

The link also runs the other way over time. In a prospective cohort of 1,955 healthcare workers followed for one year, moderate and poor sleep at baseline were associated with increased odds of developing low back pain at follow-up (Vinstrup et al., 2020).

What does pillow height change?

A radiographic study of 16 adults aged 20 to 30 measured the neck at pillow heights of 0, 10 and 20 cm. As height increased, T1 slope and C2-7 Cobb angle increased while neck tilt decreased (Kim et al., 2015).

A crossover study of 10 healthy young adults combined participant testing with finite element modeling across heights of 110 to 170 mm, and quantified how pillow height shifts cranio-cervical pressure and cervical alignment (Ren et al., 2016).

In a pilot study of 15 adults aged 18 to 30 using surface EMG, the pillow height matching each person's shoulder width produced the lowest sternocleidomastoid and trapezius activity during side sleeping and the highest comfort rating (Jiao et al., 2025).

Why do generic pillows miss?

A standard contoured pillow, not fitted to the individual, performed no better than ordinary shapes in a randomized study of 106 side sleepers (Gordon et al., 2009). No single optimal pillow height can be specified, because it depends on four variables that differ from person to person: cervical alignment, body dimension, contact pressure, and muscle activity (Lei et al., 2021).

What do we measure?

Pillowise is a fitted cervical pillow that licensed healthcare providers measure and dispense, made in seven sizes. Our sleep specialists take three measurements: shoulder width, neck circumference, and neck length. Combined with sleeping position and bed type, an algorithm identifies the best-fitting pillow from seven sizes.

Shoulder width is the measurement the EMG study found mattered most. A height matched to it produced the lowest neck and shoulder muscle activity during side sleeping (Jiao et al., 2025), and body dimension is what drives the individual optimum (Tian et al., 2025).

Dutch physiotherapist Thijs van der Hilst co-founded Pillowise in 2003 and developed the sizing algorithm from clinical practice. The fitting takes place in a licensed provider's office. Returns and exchanges are handled by Pillowise directly.

What does the research not show yet?

The mechanism studies above enrolled 9 to 16 healthy adults each, mostly under 30, and the most recent systematic review screened 29,091 records, included five studies covering 239 patients, and found no clear advantage for any pillow type in chronic neck pain (Ghosh et al., 2025). We position a fitted pillow as an adjunct to exercise, manual therapy, and other conservative care, a comfort and fit measure rather than a treatment for a condition.

What can you check at home?

Lie on your side on your current pillow and ask someone to look from behind. The head should sit level with the spine, not tipped up toward the ceiling or dropped toward the bed.

Look at the pillow itself. Pillows flatten, sleep positions shift, and a pillow chosen years ago was chosen for the sleeper you were then.

Keep the rest of the evening steady: a regular bedtime, gentle movement your therapist has given you, and a dark, quiet room. If the pillow check leaves you unsure, bring the question to your next visit.

For providers

Ask every patient about pillow type, pillow age and sleep position, along with the activity and posture questions you already ask. It is a one-line question covering a third of the day.

Tell patients the side-lying landmark and when to bring the pillow question back to you. Offer the fitting when the answer suggests a mismatch.

When a patient is starting a home program, the pillow fits naturally into the same conversation about what to do between sessions.

A fitted pillow extends the work of the visit into the hours between visits, alongside the exercise, manual therapy, and other care you are already delivering.

Common questions

Does pillow height still matter as I get older?

Pillow height changes cervical alignment and neck muscle activity, a finding measured in young adults (Kim et al., 2015; Jiao et al., 2025). No single height suits everyone, because the right height depends on variables that differ between people, body dimension among them (Lei et al., 2021). Your measurements, not your age, decide the size.

How does poor sleep relate to pain?

In hospital workers, high pain was associated with poor sleep (Vinstrup et al., 2018), and poor sleep at baseline was associated with developing low back pain a year later (Vinstrup et al., 2020). Both are observational studies in healthcare workers. Your physical therapist can help you work on both sides of that picture.

Is a contoured pillow from a store enough?

Not reliably. A standard contoured pillow, not fitted to the individual, performed no better than ordinary shapes in a randomized study of 106 side sleepers (Gordon et al., 2009), and no single optimal height can be specified because it depends on four variables that differ from person to person (Lei et al., 2021). A contour helps only if its height matches the person using it. That is what the fitting settles, in a provider's office.

Find a Pillowise provider or become one

Pillowise pillows are clinically measured and dispensed exclusively through licensed healthcare providers as part of broader sleep, posture, and recovery education.

To locate a Pillowise provider near you, visit: Find a Reseller

Licensed healthcare providers interested in offering Pillowise may register here: Become a Reseller

References

Ghosh, S. K., Goyal, M., & Goyal, K. S. (2025). Effect of pillow on pain, disability and sleep quality in patients with chronic neck pain: A systematic review. Rehabilitación, 59(3), 100922. https://doi.org/10.1016/j.rh.2025.100922

Gordon, S. J., Grimmer-Somers, K., & Trott, P. (2009). Pillow use: The behaviour of cervical pain, sleep quality and pillow comfort in side sleepers. Manual Therapy, 14(6), 671-678. https://doi.org/10.1016/j.math.2009.02.006

Jiao, R., Xiao, W., Wang, M., Yu, S., & Li, H. (2025). The impact of pillow height on neck muscle activity: A pilot study. Sleep and Breathing, 29(1), 40. https://doi.org/10.1007/s11325-024-03219-6

Kim, H. C., Jun, H. S., Kim, J. H., Ahn, J. H., Chang, I. B., Song, J. H., & Oh, J. K. (2015). The effect of different pillow heights on the parameters of cervicothoracic spine segments. Korean Journal of Spine, 12(3), 135-138. https://doi.org/10.14245/kjs.2015.12.3.135

Lei, J.-X., Yang, P.-F., Yang, A.-L., Gong, Y.-F., Shang, P., & Yuan, X.-C. (2021). Ergonomic consideration in pillow height determinants and evaluation. Healthcare, 9(10), 1333. https://doi.org/10.3390/healthcare9101333

Ren, S., Wong, D. W.-C., Yang, H., Zhou, Y., Lin, J., & Zhang, M. (2016). Effect of pillow height on the biomechanics of the head-neck complex: Investigation of the cranio-cervical pressure and cervical spine alignment. PeerJ, 4, e2397. https://doi.org/10.7717/peerj.2397

Tian, S., Yao, C., Wang, Y., Cao, X., Sun, Y., Wang, L., & Fan, Y. (2025). The individualized optimal pillow height and neck support design for side sleepers. Medical and Biological Engineering and Computing, 63(2), 535-544. https://doi.org/10.1007/s11517-024-03204-x

Vinstrup, J., Jakobsen, M. D., & Andersen, L. L. (2020). Poor sleep is a risk factor for low-back pain among healthcare workers: Prospective cohort study. International Journal of Environmental Research and Public Health, 17(3), 996. https://doi.org/10.3390/ijerph17030996

Vinstrup, J., Jakobsen, M. D., Calatayud, J., Jay, K., & Andersen, L. L. (2018). Association of stress and musculoskeletal pain with poor sleep: Cross-sectional study among 3,600 hospital workers. Frontiers in Neurology, 9, 968. https://doi.org/10.3389/fneur.2018.00968