Melempar tidak hanya berfokus pada kekuatan otot bahu, otot-otot core juga berkontribusi sekitar 55% dari energi kinetik dan gaya yang digunakan pada seluruh gerak lemparan. Oleh sebab itu, penambahan core stability exercise (CSE) pada latihan konvensional yaitu thrower’s ten exercise (TTE) sangat diperlukan untuk pemain outfielder agar terjadi peningkatan jarak lempar pada pemain tersebut. Tujuan Penelitian adalah untuk membuktikan efektivitas penambahan CSE pada TTE terhadap peningkatan jarak lempar pemain outfielder’s baseball di SMAN 8 Denpasar. Ini merupakan penelitian eksperimental menggunakan metode randomized two group pre-test and post-test, pengambilan sampel dilakukan secara simple random sampling dengan jumlah peserta sebesar 16 orang dan setelah diacak peserta dikelompokkan merata pada Kelompok Kontrol (TTE) dan Kelompok Intervensi (CSE dan TTE). Setiap kelompok diberi intervensi 3 kali seminggu dalam 6 minggu penelitian. Jarak lemparan diukur tiap 3 kali intervensi dalam 6 minggu untuk semua peserta penelitian. Hasil analisis data uji paired t-test Kelompok Kontrol diperoleh nilai (p=0,588) (p>0,05) sedangkan hasil Kelompok Intervensi (p=0,000) (p<0,05). Dari hasil tersebut, latihan pada Kelompok Intervensi signifikan meningkatkan jarak lemparan outfielder’s baseball. Hasil analisis Man Whitney U-Test di data selisih ke dua kelompok ditemukan nilai (p= 0,002) dimana (p< 0,05) yang menginterpretasikan terdapat perbedaan yang bermakna hasil jarak lemparan Kelompok Intervensi dengan Kelompok Kontrol. Berdasakan hasil analisis dapat disimpulkan ada perbedaan efektivitas pada kelompok penambahan intervensi CSE pada TTE dengan Kelompok Intervensi TTE terhadap peningkatan jarak lemparan pemain outfielders baseball di SMAN 8 Denpasar

Introduction: Osteoarthritis (OA) is the most common arthritis and one of the main causes of disability. This injury can occur in any joint, but the most common OA occurrence globally, especially in Indonesia, is Knee OA (KOA). Damage caused by KOA's degenerative process affects the knee and affects the surrounding structures, such as the lumbar vertebra, which increases symptoms of low back pain (LBP). The occurrence of symptoms of LBP is thought to be caused by knee spine syndrome, which is a condition reduced lumbar lordosis angle due to the degenerative phase of KOA. the mechanism of this syndrome has not yet been discussed in detail, so further discussion is needed in the future. Methods: We searched articles using a list of keywords, including "knee osteoarthritis and low back pain", "knee osteoarthritis and knee contracture", "knee contracture and muscle weakness", "knee contracture and spinal alignments", "knee osteoarthritis and spinal alignment", "knee osteoarthritis and sagittal spinal alignment", and "muscle activation and spinal imbalance" on the data sources of PubMed, ScienceDirect, and Google Scholar. The argumentative, descriptive analysis was used for the data analysis technique. Results: Based on the literature search, the author found four related articles. This study provides evidence of the effect of KOA on lumbar proprioception. These articles explained that an impact on knee posture could have long-term effects both in the spine and pelvis, such as lumbar lordosis. Conclusion: Knee spine syndrome results from a reduced angle of lumbar lordosis, increasing pressure between discs, which might increase LBP symptoms. In the future, it is hoped that there will be studies that raise the relationship between KOA and symptom of LBP.