PMID- 38263079 OWN - NLM STAT- MEDLINE DCOM- 20240125 LR - 20240202 IS - 1471-2474 (Electronic) IS - 1471-2474 (Linking) VI - 25 IP - 1 DP - 2024 Jan 23 TI - In vivo interrelationships between the gluteus minimus and hip joint capsule in the hip internal rotation position with flexion. PG - 87 LID - 10.1186/s12891-024-07188-5 [doi] LID - 87 AB - BACKGROUND: The flexion adduction internal rotation (FADIR) test is performed by the combined motions of hip flexion (with knee flexion), adduction, and internal rotation, and can often reproduce anterior hip pain consistent with an individual's presenting pain. Since it has high sensitivity for intraarticular pathology diagnosis but low specificity, understanding the extraarticular pathology that can induce anterior hip pain in the FADIR test may also be essential. This study hypothesized that the interrelationships between the joint capsule and gluteus minimus differ in individuals with and without FADIR-positive pain and aimed to elucidate the in vivo interrelationships at hip internal rotation in 90 degrees -flexion, which is also often restricted in individuals with FADIR-positive pain. METHODS: Ten hips were included in the FADIR-positive group, and ten hips without hip pain in the FADIR test were included in a control group. Based on the ultrasound images at the four hip rotation conditions (20 degrees and 10 degrees external rotations, 0 degrees external/internal rotation, and 10 degrees internal rotation), orientation measurements of the gluteus minimus (muscle belly portion) and joint capsule were performed and quantitatively compared between the FADIR-positive and control groups. Additionally, 3 hips of 3 participants were randomly selected from each of the control and FADIR-positive groups for magnetic resonance imaging analysis. RESULTS: At 0 degrees -external/internal and 10 degrees -internal rotation, on ultrasound images, fibers of the gluteus minimus and joint capsule in the FADIR-positive group were significantly more oriented in the same direction than those in the control group. Magnetic resonance imaging showed that the loose connective tissue between the gluteus minimus and joint capsule was prominent at 10 degrees -internal rotation in the control group, although this was not apparent in the FADIR-positive group. CONCLUSIONS: At hip internal rotation in 90 degrees flexion, the muscular belly portion of the gluteus minimus and joint capsule were oriented in the same direction to a greater extent in the FADIR-positive group than in the control group owing to a morphological change in the loose connective tissue between them. The pathological changes in the loose connective tissue may inhibit smooth movement of the gluteus minimus relative to the joint capsule in individuals with FADIR-positive pain. CI - (c) 2024. The Author(s). FAU - Tsutsumi, Masahiro AU - Tsutsumi M AD - Inclusive Medical Sciences Research Institute, Morinomiya University of Medical Sciences, 1-26-16 Nankokita, Suminoe-ku, Osaka city, 559-8611, Japan. masahiro_tsutsumi@morinomiya-u.ac.jp. AD - Department of Physical Therapy, Morinomiya University of Medical Sciences, Osaka, Japan. masahiro_tsutsumi@morinomiya-u.ac.jp. AD - Department of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. masahiro_tsutsumi@morinomiya-u.ac.jp. FAU - Saiki, Akari AU - Saiki A AD - Department of Physical Therapy, Morinomiya University of Medical Sciences, Osaka, Japan. FAU - Yamaguchi, Isao AU - Yamaguchi I AD - Department of Radiological Science, Faculty of Health Science, Morinomiya University of Medical Sciences, Osaka, Japan. FAU - Nimura, Akimoto AU - Nimura A AD - Department of Functional Joint Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. FAU - Utsunomiya, Hajime AU - Utsunomiya H AD - Tokyo Sports & Orthopaedic Clinic, Tokyo, Japan. FAU - Akita, Keiichi AU - Akita K AD - Department of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. FAU - Kudo, Shintarou AU - Kudo S AD - Inclusive Medical Sciences Research Institute, Morinomiya University of Medical Sciences, 1-26-16 Nankokita, Suminoe-ku, Osaka city, 559-8611, Japan. AD - Department of Physical Therapy, Morinomiya University of Medical Sciences, Osaka, Japan. LA - eng GR - JP 22K17645/Japan Society for the Promotion of Science/ PT - Journal Article DEP - 20240123 PL - England TA - BMC Musculoskelet Disord JT - BMC musculoskeletal disorders JID - 100968565 SB - IM MH - Humans MH - Rotation MH - *Arthralgia MH - *Pain MH - Movement MH - Joint Capsule PMC - PMC10804474 OTO - NOTNLM OT - Anterior hip pain OT - Gluteus minimus OT - Hip internal rotation OT - Joint capsule COIS- The authors declare no competing interests. EDAT- 2024/01/24 00:42 MHDA- 2024/01/25 06:43 PMCR- 2024/01/23 CRDT- 2024/01/23 23:40 PHST- 2023/04/05 00:00 [received] PHST- 2024/01/09 00:00 [accepted] PHST- 2024/01/25 06:43 [medline] PHST- 2024/01/24 00:42 [pubmed] PHST- 2024/01/23 23:40 [entrez] PHST- 2024/01/23 00:00 [pmc-release] AID - 10.1186/s12891-024-07188-5 [pii] AID - 7188 [pii] AID - 10.1186/s12891-024-07188-5 [doi] PST - epublish SO - BMC Musculoskelet Disord. 2024 Jan 23;25(1):87. doi: 10.1186/s12891-024-07188-5.