

Sitting for a long drive asks a lot of your lower back, especially when the seat is not set up to support you. Many people find their back feels stiff or achy after time behind the wheel, and often the seat can be adjusted to take some of that pressure off. A few changes to how your back is supported can make longer journeys more comfortable.
Your lower back has a gentle inward curve, and it feels most comfortable when that curve is supported rather than flattened. Without support, it is easy to slump, which leaves the muscles and discs of your lower back carrying more load.
If your seat has a lumbar support setting, you could try adjusting it so it fills the small of your back without pushing you forward. If it does not, a small rolled towel or cushion placed behind your lower back does a similar job.
A seat that is too upright can feel rigid, while one reclined too far leaves you reaching for the wheel and losing the support behind you. Somewhere slightly back from fully upright tends to feel comfortable for most people, with your back resting against the seat.
The aim is for the seat to take your weight, rather than your muscles holding you in place. If you notice yourself perching forward, away from the backrest, that is a sign to ease the angle or move closer to the wheel.
If you are stretching your legs to reach the pedals, your hips slide forward and your lower back tends to flatten and lose its support. Bringing the seat forward so your knees stay comfortably bent helps you sit back into the support behind you.
A good guide is that you can press the pedals fully without straightening your leg completely or sliding away from the backrest.
Even with a well set up seat, staying still for a long time is what tends to stiffen the back most. Where you can, breaking up a long drive with short stops gives your back a chance to move and reset.
At a stop, you could try standing tall and easing gently into a small backward lean, only as far as feels comfortable, to counter the time spent sitting.
Once you have parked, a gentle stretch helps release the stiffness that builds up from sitting. Standing tall, you could rest your hands on your lower back and ease into a small backward lean, holding for a comfortable breath or two before returning to standing, and repeating a few times.
If you would like to follow a guided version, VIDA has a short stretch video you can do at your own pace.