Working from home has its merits, but a lot of people I know have recently started complaining about its ill-effects, specifically around the 肩 (kata, shoulders) and 腰 (koshi, lower back).
When people were told to work remotely due to the コロナ禍 (korona-ka, coronavirus pandemic), not everyone had set up their own home office. That means, people working from spots like their kitchen tables or living room sofas, with 肩凝り (katakori, shoulder aches) and 腰痛 (yōtsū, lower back pain) as the result.
If you feel a 刺すような痛み (sasu yōna itami, stabbing pain) then move away from your computer and do some stretches. Or, better yet, make an appointment with a 整体師 (seitaishi, bodywork therapist) and deal with the problem before things get really bad.