A rear-end collision can happen in seconds, but the effects on the body—especially the neck and upper back—may last much longer. Many people feel “okay” right after an accident, only to notice stiffness, headaches, or worsening neck pain later that day or the next. Understanding how recovery typically works can help drivers and passengers make safer decisions, avoid unnecessary setbacks, and know when it’s appropriate to see a chiropractor for whiplash in Glendale, AZ or an auto accident chiropractor in Glendale AZ. Why symptoms often show up later after a rear-end collision Rear-end impacts commonly create a quick back-and-forth movement of the head and neck. This sudden motion can strain muscles and ligaments, irritate joints, and increase sensitivity in the tissues surrounding the cervical spine. Even when vehicle damage looks minor, the body can still experience significant force. Delayed symptoms are common because: Inflammation can build gradually over several hours Adrenaline and stress may mask pain immediately after the crash Muscle guarding may increase as the body tries to “protect” the area Stiffness can worsen overnight after periods of inactivity This is why it’s often recommended to monitor symptoms closely for 24–72 hours after an accident. Common signs of whiplash-related neck and upper back strain Not all neck pain after a collision is whiplash, but many cases share similar patterns. People often report: Neck stiffness or reduced ability to turn the head Pain when looking over the shoulder or looking up/down Headaches that start at the base of the skull Upper back tightness between the shoulder blades Shoulder discomfort that feels connected to the neck Increased pain after sitting, driving, or working at a screen Sleep disruption due to difficulty finding a comfortable position These symptoms may range from mild to severe. The key...