Hip Orthopaedic Test: Bowstring Sign

The Bowstring Sign is used after a straight leg raise position to assess whether pressure in the popliteal fossa reproduces familiar neural-type leg symptoms. A positive finding may support suspicion of sciatic nerve or lumbosacral nerve-root mechanosensitivity when it matches the client’s symptoms and history. High-quality diagnostic accuracy evidence for the exact test is limited, so it should be interpreted alongside neurological findings, SLR, slump testing and symptom behaviour.

Introduction

A client with low-back-related leg pain may report symptoms travelling into the posterior thigh, calf or foot. The Bowstring Sign can add context after a straight leg raise by applying pressure behind the knee to assess whether familiar neural-type symptoms are reproduced.

Recent literature on lumbar radiculopathy emphasises that neurodynamic and orthopaedic tension tests should be interpreted as part of a broader examination rather than as stand-alone diagnostic tools. The Straight Leg Raise, Slump and related tests can assist clinical reasoning, but accuracy varies with population, reference standard and symptom definition.  

Quick Summary

Test name: Bowstring Sign
Also known as: Bowstring Test, Cram Test, popliteal pressure sign
Purpose: Assess symptom response to sciatic nerve tension or mechanosensitivity
Body region: Lumbar spine, posterior thigh and sciatic nerve pathway
Commonly associated presentation: Low-back-related leg pain, suspected lumbosacral radicular symptoms, sciatic nerve mechanosensitivity
Positive finding: Familiar posterior leg or radicular-type symptoms reproduced by popliteal pressure after SLR positioning
Negative finding: No familiar neural-type symptoms reproduced
Best used with: Straight Leg Raise, Slump Test, neurological screen, dermatomes, myotomes, reflexes and symptom behaviour
Key limitation: Exact diagnostic accuracy evidence is limited

What Is the Bowstring Sign?

The Bowstring Sign is a neurodynamic test commonly performed after raising the client’s straight leg to the point where symptoms are reproduced or tension is felt. The knee may then be slightly flexed and pressure is applied over the popliteal fossa or tibial nerve region to assess whether familiar symptoms are reproduced.

It is intended to help distinguish neural-type symptoms from non-neural posterior thigh tightness, but it does not confirm nerve-root involvement on its own.

Why It Is Used

The Bowstring Sign is used when low-back-related leg symptoms or sciatic nerve mechanosensitivity are suspected. It may help clarify whether symptoms are reproduced by neural tissue loading rather than hamstring stretch alone.

What It Assesses

The test assesses symptom response to combined lower-limb neural loading and local pressure around the popliteal fossa.

It does not identify the exact spinal level, prove disc involvement, confirm radiculopathy or exclude other causes of posterior thigh or leg symptoms.

Who It Is Useful For

This test may be useful for clients with posterior thigh or leg symptoms, suspected radicular features, symptoms changed by lumbar movement, or unclear differentiation between hamstring stretch and neural symptoms.

It may not be suitable when pain is highly irritable, the client cannot tolerate SLR positioning, neurological signs are rapidly worsening, or urgent referral features are present.

When to Use This Test

Use the test when the client’s history and symptom distribution suggest neural sensitivity and when adding popliteal pressure after SLR may clarify symptom behaviour.

When Not to Use or When to Be Cautious

Use caution with severe or worsening neurological symptoms, suspected cauda equina features, unexplained progressive weakness, acute trauma, severe irritability, vascular concern, or symptoms that escalate quickly during testing.

Equipment Required

Treatment table
Pain scale
Measurz for recording
Optional inclinometer for SLR angle
Optional neurological screen notes
Optional comparison side notes

Step-by-Step Protocol / Practice

Setup

Position the client supine with both legs relaxed.

Client position

Keep the tested knee extended and raise the leg into a straight leg raise until familiar symptoms, neural tension or the selected stopping point is reached.

Examiner position

Stand beside the tested limb and support the leg.

Hand placement

Support the heel or lower leg with one hand. Use the other hand to apply controlled pressure to the popliteal fossa or tibial nerve region after slightly easing the knee position if required.

Stabilisation

Keep the pelvis and opposite leg stable. Avoid forcing hip flexion.

Movement or force direction

Raise the leg into SLR, identify the symptom angle, then apply controlled pressure behind the knee.

Instructions

Ask the client to report whether the pressure reproduces familiar leg symptoms, altered sensation, tingling, pulling or pain.

Positive finding

A positive finding is reproduction of familiar posterior leg or neural-type symptoms with popliteal pressure.

Negative finding

A negative finding is no reproduction of familiar neural-type symptoms.

Stopping criteria

Stop if symptoms become sharp, severe, spreading, neurologically concerning or slow to settle.

Safety notes

Do not force the leg into high-range SLR. Record whether symptoms are familiar and whether they change with sensitising or easing movements.

Positive and Negative Test Interpretation

A positive Bowstring Sign may increase suspicion of sciatic nerve or lumbosacral nerve-root mechanosensitivity when it reproduces the client’s familiar symptoms and matches the broader presentation.

A negative test may reduce suspicion that popliteal pressure in this position reproduces neural symptoms, but it does not exclude radicular pain, disc involvement or neural sensitivity.

Interpretation is stronger when combined with SLR angle, Slump Test, neurological screen, symptom distribution, lumbar movement response and irritability.

Sensitivity, Specificity and Diagnostic Accuracy

High-quality diagnostic accuracy evidence for the exact Bowstring Sign is limited. Recent neurodynamic test research more commonly evaluates SLR, Slump and combinations of neurodynamic or orthopaedic tension tests rather than Bowstring Sign alone. A 2020 study on neurodynamic and orthopaedic tension tests suggested that combinations of tests may have greater clinical value than individual tests for lumbar or lumbosacral radicular presentations.  

A 2020 review article discussed how Bowstring and Slump testing may add clinical value when SLR is ambiguous, but robust sensitivity, specificity and likelihood ratios for Bowstring Sign alone are not well established.  

Reliability and Validity

Reliability depends on SLR angle, pressure location, amount of force, symptom criteria, client irritability and examiner consistency.

Validity is strongest when the test reproduces familiar neural-type symptoms and aligns with other neurodynamic, neurological and history findings.

Common Errors and Limitations

Common errors include applying pressure too aggressively, failing to record the SLR angle, interpreting hamstring stretch as neural symptoms, not comparing sides and ignoring neurological red flags.

Limitations include limited exact-test accuracy evidence, symptom overlap and examiner-dependent pressure.

Practical Applications

Use the Bowstring Sign to document whether neural-type symptoms can be reproduced and to support clinical reasoning around low-back-related leg symptoms.

How to Record This in Measurz

Record test name, side tested, result as positive, negative, unclear or unable to test, SLR angle, pressure location, pain score, symptom location, symptom quality, neural symptoms, comparison side, irritability, confidence in result, reason for stopping and related neurological findings.

Related Tests / Internal Links

Straight Leg Raise Test
Slump Test
Bragard Sign Test
Femoral Nerve Tension Test
Lumbar ROM Tests
Hip ROM Tests
Neurological Screen

FAQs

What does the Bowstring Sign assess?

It assesses whether pressure behind the knee during or after SLR reproduces familiar neural-type leg symptoms.

What is a positive Bowstring Sign?

A positive finding is reproduction of familiar posterior leg, tingling, pulling or radicular-type symptoms with popliteal pressure.

Does the Bowstring Sign diagnose radiculopathy?

No. It may support clinical reasoning but does not confirm radiculopathy on its own.

Why record the SLR angle?

The angle helps repeat the test and interpret whether symptoms occur at a consistent range.

What should be recorded?

Record SLR angle, pressure location, symptom location, symptom quality and comparison side.

Key Takeaways

The Bowstring Sign is a neurodynamic symptom provocation test.
A positive result may suggest neural mechanosensitivity when symptoms are familiar.
Exact diagnostic accuracy evidence is limited.
It should be interpreted with SLR, Slump and neurological findings.
Use Measurz to record angle, symptoms, pressure site and confidence.

References

Bueno-Gracia, E., et al. (2020). Use of neurodynamic or orthopedic tension tests for the diagnosis of lumbar and lumbosacral radiculopathy: Study of the diagnostic validity. International Journal of Environmental Research and Public Health, 17(19), 7046. https://doi.org/10.3390/ijerph17197046 

Rade, M., Shacklock, M., & Kononen, M. (2020). Inadequacies of the Lasègue test, and how the Slump and Bowstring tests are useful for the diagnosis of sciatica. Neurochirurgie, 66(6), 401–405. Needs verification.

van der Windt, D. A., et al. (2010). Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain. Cochrane Database of Systematic Reviews. Older landmark source retained for context.