{"id":9639,"date":"2022-01-20T15:59:56","date_gmt":"2022-01-20T14:59:56","guid":{"rendered":"https:\/\/www.physiotutors.com\/?post_type=wiki&#038;p=9639"},"modified":"2026-10-15T18:29:41","modified_gmt":"2026-10-15T16:29:41","slug":"prone-knee-bending-test","status":"publish","type":"wiki","link":"https:\/\/www.physiotutors.com\/wiki\/prone-knee-bending-test\/","title":{"rendered":"Prone Knee Bending Test"},"featured_media":0,"template":"","meta":{"_acf_changed":false,"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":""},"class_list":["post-9639","wiki","type-wiki","status-publish","hentry"],"acf":{"free_access":"","app_link":"","sections":[{"acf_fc_layout":"page-header-detail-page","background":{"background_image":9640,"background_image_alt_text":"Prone Knee Bending Test"},"heading":"Prone Knee Bending Test | Reversed Las\u00e8gue Test | Femoral Nerve Test","subheading":"Lumbar Spine Assessment","content_editor":"","button_type":"internal_link","button_label":"Check our shop","button_style":"button-five","button_internal_link":4646,"button_anchor":"","button_url":"","button_file":null,"label":""},{"acf_fc_layout":"submenu","links":[{"button_type":"anchor","button_label":"Learn","button_internal_link":null,"button_anchor":"section-number-3","button_url":"","button_file":null},{"button_type":"anchor","button_label":"Free course","button_internal_link":null,"button_anchor":"section-number-5","button_url":"","button_file":null},{"button_type":"anchor","button_label":"Assessment E-Book","button_internal_link":null,"button_anchor":"section-number-6","button_url":"","button_file":null}],"dropdown_label":"Go to","button_right":{"button_type":"internal_link","button_label":"Try Premium free","button_style":"button-three","button_internal_link":26802,"button_anchor":"","button_url":"","button_file":""},"button_description":""},{"acf_fc_layout":"content-content","section_options":{"vertical_alignment":"top","column_right_box":false,"column_left_width":"col-12 col-lg-4 offset"},"column_left":{"content_editor":"<h4>Learn<\/h4>"},"column_right":{"content_editor":"<h6>Prone Knee Bending Test | Reversed Las\u00e8gue Test | Femoral Nerve Test<\/h2>\nThe diagnosis of lumbar radicular syndrome is commonly made by patient-history alone and additional testing to confirm this hypothesis is often not necessary. 90% of cases involve nerve roots L4-L5 or L5-S1, as those segments are exposed to the highest static and kinetic forces.\nTo make a diagnosis of lumbar disc herniation with root compression at those levels more likely, the crossed straight leg raise can be used as it tensions the sciatic nerve. While uncommon at around 5% of cases, lumbar disc herniations with nerve root compression do occur at L3-L4 and to an even lesser degree at levels above.\n\n<a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/20543768\/\" target=\"_blank\" rel=\"noopener\">Suri et al. (2011)<\/a> investigated the diagnostic accuracy of the prone knee bend for lumbar disc herniation with nerve root compression at L2-L4 and found a sensitivity of 50% and specificity of 100%. For nerve root L3 only, the sensitivity was 70% and specificity 88% so it has a moderate clinical value to make the diagnosis more likely.\n<div class=\"embed-container\">\n\n[embed]https:\/\/www.youtube.com\/watch?v=whb3Rknage0[\/embed]\n\n<\/div>\nTo conduct the test the patient lies in prone position. Then proceed to carefully flex the knee on the affected side maximally.\nIf you\u2019re unable to flex the knee further than 90\u00b0 or if you want to emphasize stretch on the femoral nerve even further you may add passive hip extension.\n\nThe test is considered positive in case the patient reports shooting pain down the leg or anterior thigh upon maximal knee flexion with or without added hip flexion.\nSome authors recommend holding the knee flexion for 45-60 seconds though that may be too provocative in an active nerve root compression.\n\nOther common orthopedic tests to assess for lumbosacral radicular pain are:\n<ul>\n \t<li><a href=\"https:\/\/www.physiotutors.com\/wiki\/straight-leg-raise-test\/\" target=\"_blank\" rel=\"noopener\">Straight Leg Raise Test (SLR) \/ Las\u00e8gue Test<\/a><\/li>\n \t<li><a href=\"https:\/\/www.physiotutors.com\/wiki\/crossed-straight-leg-raise-test\/\">Crossed SLR (lower sensitivity, but higher specificity)<\/a><\/li>\n \t<li><a href=\"https:\/\/www.physiotutors.com\/wiki\/bowstring-test\/\">Bowstring Test<\/a><\/li>\n \t<li><a href=\"https:\/\/www.physiotutors.com\/wiki\/slump-test\/\">Slump Test<\/a><\/li>\n<\/ul>\n&nbsp;\n"}},{"acf_fc_layout":"content-content","section_options":{"vertical_alignment":"top","column_right_box":false,"column_left_width":"col-12 col-lg-4 offset"},"column_left":{"content_editor":"<h4>References<\/h4>"},"column_right":{"content_editor":"<a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/20543768\/\" target=\"_blank\" rel=\"noopener\">Suri P, Rainville J, Katz JN, Jouve C, Hartigan C, Limke J, Pena E, Li L, Swaim B, Hunter DJ. The accuracy of the physical examination for the diagnosis of midlumbar and low lumbar nerve root impingement. Spine. 2011 Jan 1;36(1):63.<\/a>"}},{"acf_fc_layout":"cta-form-v2","content_editor":"<h2>Want to get better at treating <strong>low back pain?<\/strong><\/h2>\r\n<p>Take our <strong>free<\/strong> 5-day email course on low back pain, from imaging to the best exercise, straight to your inbox.<\/p>","form":"37","image":29334,"image_alt_text":"Free low back pain email course"},{"acf_fc_layout":"cta-image-v2","layout":"","background":"transparent","heading":"","content_editor":"<p class=\"subheading\">Like what you\u2019re learning?<\/p>\n<p class=\"heading-two\">Get the full Physiotutors <strong>Assessment Book<\/strong><\/p>\n\n<ul>\n \t<li>600+ pages on orthopedic assessment<\/li>\n \t<li>Video demonstrations and direct links to the PubMed studies<\/li>\n \t<li>Statistical values for every special test, from the latest research<\/li>\n \t<li>Free lifetime updates<\/li>\n \t<li>Available in English, German, French, Spanish, Italian, Portuguese and Turkish<\/li>\n<\/ul>","button_type":"internal_link","button_label":"See the Assessment Book","button_style":"button-two","button_internal_link":4646,"button_anchor":"","button_url":"","button_file":null,"side_button":{"side_button_content_editor":""},"bottom_button":{"bottom_button_content_editor":""},"image":22705,"image_alt_text":""}]},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.8 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Prone Knee Bending Test | Reversed Las\u00e8gue \/Femoral Nerve Test<\/title>\n<meta name=\"description\" content=\"The Prone Knee Bending Test aka Reversed Las\u00e8gue Test is a test to radicular pain due to nerve root compression at lumbar levels L4 and above\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.physiotutors.com\/wiki\/prone-knee-bending-test\/\" \/>\n<meta property=\"og:locale\" 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