It's always a bummer when an unexpected injury to you or your horse makes riding impossible. Not to mention, those of us without access to indoor arenas probably find poor weather a pretty big setback. Whatever your reason, sometimes not being able to ride comes as a blessing in disguise. Being free from the pressure of working your horse under saddle allows you to focus on your relationship with your horse.
Working on groundwork not only allows you to bond with your horse, but it also allows the horse to use both his mind and body while not under saddle.
This is a great way for you, as a rider, to take time to consider your horse's individual needs and either organize a list of exercises appropriate for his fitness level, or create your own.
Assuming your horse is in good health, try taking your horse's vitals several times to get a feel for his normal stats. This information can come in handy later on.
Keep your horse happy and healthy: mentally!
Again, assuming your horse is healthy and capable of at least groundwork, in-hand work is a fantastic way to improve your connection with your horse. Both body language, reaction time, muscle, concentration are all benefits from properly conducted in-hand work.
Let your horse exercise both his legs and mind while you (hopefully) take a relaxing walk around the property. If possible, you could let him graze, or even use some of the surroundings to desensitize your horse.
In the case that your horse can't be ridden, take this newfound freedom to work on your fitness for riding. You'll come back a stronger, more precise rider for your horse.
Similarly, use your time to audit some clinics. This is another great way to come back with more knowledge and experience. On the plus side, auditing a clinic is usually much cheaper than attending one as a rider. If you want another way to improve your knowledge, see below!
Okay, I mean, what's been one of the best ways to communicate useful information since writing was invented? Yup. Books, y'all...books. Hit 'em up.
Try a fun DIY that will come in handy. Usually, you can make some things pretty cheap, so if you are tight on funds (let's be honest, if you own a horse that can't be ridden for medical reasons, this is probably the case!) this might be a great option for you!
Take your horse's time off and use it to spruce up the rest of your barn! Clean out the hay loft, powerwash the aisles, or do whatever has been on your to-do list for awhile.
Honestly, there's not much to say for this one.
If you are looking for MORE ideas, check out: https://www.horsetricks101.com/2015/09/31-things-to-do-with-your-horse-other-than-riding/
If you find yourself in a funk, or you can't ride, try some of these activities. You might be surprised by how many things you can do without working your horse under saddle! Have fun!