Beyond intensity: A commentary on stretch-induced hypoalgesia

Abstract

We read with great interest the recent study by Støve et al., examining stretching intensity and pain sensitivity which demonstrated that both low- and high-intensity stretching produced similar hypoalgesic effects (Støve et al., 2024). This finding raises two important questions: Why would anyone need to perform high-intensity stretching if lower intensities achieve comparable pain modulation? And more fundamentally, how does body position—a question raised by Apostolopoulos et al. almost 10 years ago (Apostolopoulos et al., 2015) still unanswered—influence these stretching effects?

Their results showed that stretching exercises activate ‘endogenous modulation of somatosensory input’, with more pronounced effects at regional sites compared to distant sites. While their standardized protocol using a seated position in the Biodex system provided good experimental control, it may limit generalizability to clinical practice where stretching is performed in various positions. The interaction between body position, gravitational effects and pain modulation pathways could significantly influence both local and systemic responses (Cooper et al., 2023).

The clinical implications extend beyond simple stretching exercises. Traditional movement practices like yoga and Chinese exercises (e.g. Baduanjin) incorporate various stretching intensities, potentially activating similar pain-modulating pathways (Wang et al., 2021). Understanding whether the intensity-independent hypoalgesic effect holds true across different positions and delivery methods would advance therapeutic applications. This is particularly relevant given that the mechanical loading and proprioceptive input may vary significantly with body position.

These findings could guide clinicians in prescribing stretching exercises, suggesting that gentler approaches might be equally effective for pain management. However, future research should examine not only the effects in diverse populations but also how different body positions might influence stretching intensity and subsequent pain modulation outcomes.