{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T16:01:36Z","timestamp":1777046496266,"version":"3.51.4"},"reference-count":23,"publisher":"BMJ","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Br J Sports Med"],"published-print":{"date-parts":[[2008,2]]},"abstract":"Subject:<\/jats:title>Conservative treatment of patellar chondromalacia has been the subject of several studies. One recommended treatment is a strengthening exercise of the quadriceps muscle, which may be performed in closed or open kinetic chains. This study was designed to compare the effect of straight leg raise (SLR) and semi-squat exercises on the treatment of patellar chondromalacia, which has not been done to date.<\/jats:p><\/jats:sec>Material and methods:<\/jats:title>32 female university students with a diagnosis of patellar chondromalacia were randomly assigned to two experimental groups: SLR and semi-squat exercise. Before starting exercise protocols, Q angle, maximal isometric voluntary contraction force (MIVCF) of quadriceps, crepitation, circumference of thigh 5 and 10 cm above the patella and patellofemoral pain according to the visual analogue scale (VAS) were assessed. Both groups then followed a 3-week programme of quadriceps muscle strengthening exercises (SLR or semi-squat) starting with 20 exercises twice a day and increasing each session by 5 exercises every 2 days. All measurements were repeated at the end of each week and then again 2 weeks after the 3-week exercise programme.<\/jats:p><\/jats:sec>Results:<\/jats:title>Reduced Q angle (mean differences (SD) 0.8 (0.3), p\u200a=\u200a0.016) and crepitation (19.9 (8.5), p\u200a=\u200a0.04), and an increase in the MIVCF of the quadriceps (15.8 (5.6), p\u200a=\u200a0.01) and thigh circumference (1.5 (0.3), p\u200a=\u200a0.001) were found in semi-squat group compared with SLR group. However, patellofemoral pain was decreased significantly in both groups.<\/jats:p><\/jats:sec>Conclusion:<\/jats:title>The results of this study indicate that semi-squat exercises (closed kinetic chain) are more effective than SLR exercise (open kinetic chain) in the treatment of patellar chondromalacia. More studies are needed to investigate the long-term effect of these types of exercise.<\/jats:p><\/jats:sec>","DOI":"10.1136\/bjsm.2007.038109","type":"journal-article","created":{"date-parts":[[2007,7,6]],"date-time":"2007-07-06T01:19:58Z","timestamp":1183684798000},"page":"99-102","source":"Crossref","is-referenced-by-count":45,"title":["Open versus closed kinetic chain exercises for patellar chondromalacia"],"prefix":"10.1136","volume":"42","author":[{"given":"A H","family":"Bakhtiary","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E","family":"Fatemi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2007,7,5]]},"reference":[{"issue":"(5)","key":"2024051313115868000_42.2.99.1","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1097\/01241398-198212000-00017","article-title":"Chondromalacia of the patella.","volume":"2","author":"Casscells","year":"1982","journal-title":"J Pediatr Orthop"},{"key":"2024051313115868000_42.2.99.2","doi-asserted-by":"publisher","DOI":"10.1136\/bjsm.2002.002964"},{"key":"2024051313115868000_42.2.99.3","first-page":"342","article-title":"Patella pain syndromes and chondromalacia patellae.","volume":"30","author":"Insall","year":"1981","journal-title":"Instr Course Lect"},{"key":"2024051313115868000_42.2.99.4","first-page":"S68","article-title":"Patellar crepitation in the P.F.C. sigma total knee system.","volume":"29","author":"Ranawat","year":"2006","journal-title":"Orthopedics"},{"key":"2024051313115868000_42.2.99.5","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1097\/01.blo.0000172306.97285.95","article-title":"Patellofemoral pain: results of nonoperative treatment.","volume":"436","author":"Post","year":"2005","journal-title":"Clin Orthop Relat Res"},{"issue":"(10)","key":"2024051313115868000_42.2.99.6","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1053\/apmr.2001.26252","article-title":"Vastus medialis and Vastus lateralis activity in open & closed kinetic chain exercises in patients with patellofemoral pain syndrome: an electromyographic study.","volume":"52","author":"Tang","year":"2001","journal-title":"Arch Phys Med Rehabil"},{"issue":"(3)","key":"2024051313115868000_42.2.99.7","doi-asserted-by":"crossref","first-page":"197","DOI":"10.2519\/jospt.1998.27.3.197","article-title":"Comparison of five isometric exercises in the recruitment of the vastus medialis oblique in persons with and without patellofemoral pain syndrome.","volume":"27","author":"Laprade","year":"1998","journal-title":"J Orthop Sports Phys Ther"},{"issue":"(2)","key":"2024051313115868000_42.2.99.8","doi-asserted-by":"crossref","first-page":"104","DOI":"10.2519\/jospt.1996.23.2.104","article-title":"The effect of open and closed chain exercise and knee joint position on patellar tracking in lateral patellar compression syndrome.","volume":"23","author":"Doucette","year":"1996","journal-title":"J Orthop Sports Phys Ther"},{"issue":"(4)","key":"2024051313115868000_42.2.99.9","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1097\/00005768-199804000-00014","article-title":"Biomechanics of the knee during closed and open kinetic chain exercises.","volume":"30","author":"Escamilla","year":"1998","journal-title":"Med Sci Sports Exerc"},{"issue":"(9)","key":"2024051313115868000_42.2.99.10","doi-asserted-by":"crossref","first-page":"1552","DOI":"10.1097\/00005768-200109000-00020","article-title":"Effects of technique variations on knee biomechanics during the squat.","volume":"33","author":"Escamilla","year":"2001","journal-title":"Med Sci Sports Exerc"},{"issue":"(3)","key":"2024051313115868000_42.2.99.11","doi-asserted-by":"crossref","first-page":"197","DOI":"10.2519\/jospt.1998.27.3.197","article-title":"Comparison of five isometric exercises in the recruitment of the vastus medialis oblique in persons with and without patellofemoral pain syndrome.","volume":"27","author":"Laprade","year":"1998","journal-title":"J Orthop Sports Phys Ther"},{"key":"2024051313115868000_42.2.99.12","doi-asserted-by":"publisher","DOI":"10.1136\/bjsm.2005.018630"},{"key":"2024051313115868000_42.2.99.13","unstructured":"Houglum PA . 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