What Causes Tight Hamstrings and Why Stretching Sometimes Fails
What’s really causing your patients’ “tight hamstrings” in up to 76% of patients? Find out in this new study by Pesesse et al. (2025).
The authors assessed 178 asymptomatic adults to determine whether the discomfort limiting their hamstring range of movement (ROM) was muscular or neural.
They split them into two groups, who received one of the following assessment tests:
- Straight leg raise (SLR), or
- Knee extension angle (KEA)—taking them into 90 degrees of hip flexion, then passively extending the knee.
The patient said “stop” when they felt any discomfort in the leg.
While they maintained the leg position, the thoracic (T/Sp) and cervical spines (C/Sp) were passively flexed to end range (strong resistance to movement), and they were asked if the symptoms increased, decreased, or stayed the same.
They then passively extended the T/Sp and C/Sp using the movable part of the table and asked if their symptoms changed.
What did changing the C/sp and T/sp positions tell them about the hamstrings?
If their level of stretch increased with thoracic spine and cervical spine flexion and decreased with extension (moving joints that are a long way from the leg), they considered it neural in origin.
If there was no change, it was considered muscular in origin.
What did they find?
Hamstring resistance was neural in 72 to 76% of people.
What are our clinical takeaways?
If you think your patient has tight hamstrings, their ROM is unlikely to be limited by their hamstrings!
You can add C/sp and T/sp flexion/extension to your SLR or KEA to identify any changes in symptoms and whether it is actually neural, rather than muscular, in origin.
An action item for you this week
Measure either SLR or KEA in your knee, low back, and/or hip pain patients this week. Let’s say they experience discomfort at 60° SLR.
You probably won’t have someone else around just to add in C/sp and T/sp flexion and extension for you, so you could use active flexion, asking them to bring their chin to their chest, and asking if symptoms are the same/better/worse.
You can then lower the headrest down for C/sp and T/sp extension and see if symptoms change at the range you previously measured (in this case, 60°).
You can then identify if their restriction is likely neural or muscular.
Reply to this email and let me know what results you get. I’d love to hear how you go!
If persistent hamstring tightness or limited mobility is affecting your daily movement, a proper assessment can make all the difference. Our physical therapy services focus on identifying whether restrictions are muscular or neural, so treatment is targeted and effective—not guesswork.
Schedule an assessment today and get clarity on what’s really limiting your flexibility.
Take the next step toward better movement and long-term relief with expert care from OrthoWell Physical Therapy.