“…Sum vector magnitude (F5) has been used in most studies for detecting abnormal signals. The highest peak during the sudden change of this value is used to indicate a fall [ 32 , 38 , 46 , 48 – 50 , 53 , 65 , 67 – 70 , 72 – 75 , 77 – 82 , 84 – 86 , 89 – 91 , 93 , 96 , 97 , 101 , 102 , 104 , 106 , 107 ]. In [ 85 ], F5 was used to indicate the free-fall state ( i.e.…”