The effect of six-week regular stretching exercises on regional and distant pain sensitivity: an experimental longitudinal study on healthy adults

Key Points

1. Although current evidence shows a clinically relevant effect of acute stretching on musculoskeletal pain, there is limited and conflicting knowledge of the effect of regular stretching exercises on regional and widespread pain sensitivity.
2. If stretching exercises can reduce pain sensitivity over time, it would allow an additional low-cost and low risk treatment option for patients experiencing pain, however, applying stretching exercises for pain management in different patient populations requires understanding the mechanisms underlying the potential change in pain sensitivity.
3. Results of this study demonstrated six weeks of regular stretching exercises significantly decreased regional and widespread pain sensitivity.

BACKGROUND & OBJECTIVE

Stretching exercises are widely used for pain relief and show positive effects on musculoskeletal, nociplastic and neuropathic pain (1-3). However, the magnitude of altered pain sensitivity responses following regular stretching is currently unknown. Current evidence suggests that the main contributor to the effects of stretching exercises are caused by modifications in the subject’s sensation (i.e. stretch, tightness, or pain), resulting in changes in the tolerance to stretch (4). Stretch tolerance is defined as the capability to tolerate stretch-related discomfort (5).

Previous research indicates that changes in the range of motion following stretching may be a manifestation of altered pain sensitivity, suggesting that the tolerance to stretching may be a marker of overall pain sensitivity (6-9). The increase in stretch tolerance may be contingent on an analgesic effect, allowing for a higher tolerance to passive tension. The gain in flexibility following regular stretching will likely abate when stretching is discontinued, suggesting that the retention of changes in the tolerance to stretch is linked with regular modifications of somatosensory input, e.g. regular stretching (9,10).

However, there is a limited scientific understanding of the way in which these changes in pain sensitivity respond when regular stretching is discontinued.

The primary objective of this study was to investigate the effect of six weeks of regular stretching on regional and distant pain sensitivity. The secondary objective of this study was to investigate if regional and distant pain sensitivity decreased following cessation.

Stretching exercises are widely used for pain relief and show positive effects on musculoskeletal, nociplastic and neuropathic pain.

Stretching distant from the primary pain site may provide relief when local stretching is too painful to perform, which may make stretching an accessible and versatile intervention.

METHODS

• The study design was a single-blind longitudinal repeated measurement study.

• 26 participants (minimum threshold for sufficient powering) were recruited via advertisements at the University College of Northern Denmark and social media. Healthy subjects aged 18-65 years, naive to experimental pain testing, were eligible.

• Exclusion Criteria:

  • Cognitive, neurological, orthopedic, or neuromuscular problems preventing knee stretching or range of motion testing.
  • Regular participation in flexibility training (e.g. yoga, pilates, tai chi).
  • Regular use of medications affecting somatosensory systems, such as psychotropics or analgesics.

• Intervention: see Video 1 for stretching intervention

• Outcomes:

  • The primary outcome was pain sensitivity, measured as regional (segmental pain modulation) and distant (central pain modulation) pressure pain thresholds.
  • Assessments were conducted at baseline, post-stretch (six weeks), and post-cessation (ten weeks).
  • Pressure pain thresholds were measured using a handheld electronic algometer with a 1 cm² probe at two sites: tibialis anterior (regional) and deltoid (distant). A single investigator performed all measurements to avoid inter-rater discrepancies.
  • Measurements were taken independently, not following a stretching session.

STRETCHING INTERVENTION

RESULTS

Upon analysis of the study data, there was a main effect of time on pressure pain thresholds at the tibialis anterior site. Post hoc tests demonstrated a 36.7% increase in pressure pain thresholds from baseline to post-stretch, a 2.0% increase in pressure pain thresholds between post-stretch and post-cessation, and a 41.2% increase in pressure pain thresholds from baseline to post-cessation at the tibialis anterior site.

A main effect of time was found, showing a statistically significant difference in pressure pain thresholds at the deltoid site. Post hoc tests demonstrated an 18.7% increase in pressure pain thresholds from baseline to post-stretch, a 5.2% decline in pressure pain thresholds from post-stretch to post-cessation, and a 15.4% increase in pressure pain thresholds from baseline to post-cessation at the deltoid site. Pressure pain thresholds were higher at the regional site compared to the distant site. However, no between-site differences in the relative changes in pressure pain threshold from baseline to post-stretch or post-stretch to post-cassation was found.

LIMITATIONS

It is important to note that the present study included only healthy young adults, and findings may differ in different patient populations in which central and peripheral pain modulatory mechanisms are impaired (fibromyalgia and other chronic overlapping pain conditions) so caution should be taken with overgeneralization.

CLINICAL IMPLICATIONS

The main findings showed that both regional and widespread pain sensitivity significantly decreased after six weeks of regular stretching. Interestingly, the hypoalgesic effects persisted even after four weeks of cessation. This finding aligns with prior evidence suggesting that regular stretching produces long-lasting effects on regional thermal pain sensitivity.

Furthermore, the study highlighted multisegmented hypoalgesic manifestations, pointing toward the activation of widespread central inhibitory mechanisms. This is supported by the significant correlations between regional and widespread pain thresholds, indicating potential mediation through a common or central mechanism. Additionally, changes in sympathetic/parasympathetic balance, possibly driven by mechanosensory end organ activation, may also contribute to these effects, suggesting a multifaceted mechanism behind the analgesic response.

Stretching exercises should strongly be considered as a therapeutic option for patients with musculoskeletal pain. Notably, stretching distant from the primary pain site may provide relief when local stretching is too painful to perform. This approach broadens its applicability, making it an accessible and versatile intervention. Stretching is not only low-cost and low-risk but also requires no specialized equipment and minimal time commitment to achieve meaningful pain reduction.

Importantly, adherence to the intervention plays a critical role in its efficacy. The study’s adherence rate of 87.2%, considered very high, underscores the importance of implementing strategies to maintain patient compliance. Clinicians should focus on fostering high adherence to ensure optimal outcomes, replicating the positive results observed in controlled research environments.

+STUDY REFERENCE

Støve M, Thomsen J, Magnusson S, Riis A (2024) The effect of six-week regular stretching exercises on regional and distant pain sensitivity: an experimental longitudinal study on healthy adults. BMC Sports Science, Medicine and Rehabilitation, 16(1), 202.

SUPPORTING REFERENCE

1. Behm DG, Kay AD, Trajano GS, Alizadeh S, Blazevich AJ. Effects of acute and chronic stretching on pain control. J Clin Exerc Physiol. 2021;10:15–159.
2. Zhang YH, Hu HY, Xiong YC, Peng C, Hu L, Kong YZ et al. Exercise for Neuropathic Pain: a systematic Review and Expert Consensus. Front Med. 2021;8 November.
3. Ferro Moura Franco K, Lenoir D, dos Santos Franco YR, Jandre Reis FJ, Nunes Cabral CM, Meeus M. Prescription of exercises for the treatment of chronic pain along the continuum of nociplastic pain: a systematic review with meta-analysis. Eur J Pain (United Kingdom). 2020; September:1–20.
4. Magnusson SP, Simonsen EB, Aagaard P, Dyhre-Poulsen P, McHugh MP, Kjaer M. Mechanical and physical responses to stretching with and without pre-isometric contraction in human skeletal muscle. Arch Phys Med Rehabil. 1996;77:373–8.
5. Law RY, Harvey LA, Nicholas MK, Tonkin L, De Sousa M, Finniss DG. Stretch exercises increase tolerance to stretch in patients with chronic musculoskeletal pain: a randomized controlled trial. Phys Ther. 2009;89:1016–26.
6. Støve MP, Hirata RP, Palsson TS. Muscle stretching - the potential role of endogenous pain inhibitory modulation on stretch tolerance. Scand J Pain. 2019;19:415–22.
7. Bishop MD, George SZ. Pain sensitivity and torque used during measurement predicts change in range of motion at the knee. J Pain Res. 2017;10:2711–6.
8. Støve MP, Hirata RP, Palsson TS. The tolerance to stretch is linked with endogenous modulation of pain. Scand J Pain. 2021;21:355–63.
9. Knudson D. The biomechanics of stretching. J Exerc Sci Physiother. 2006;2:3–12.
10. Støve MP, Hirata RP, Palsson TS. Regional and widespread Pain Sensitivity decreases following stretching in both men and women – indications of Stretch-Induced Hypoalgesia. J Bodyw Mov Ther. 2024.
11. Willy RW, Kyle BA, Moore SA, Chleboun GS. Effect of cessation and resumption of static hamstring muscle stretching on joint range of motion. J Orthop Sports Phys Ther. 2001;31:138–44.