A 45-year-old office worker presents with 3 weeks of low back pain after lifting a heavy box. The pain is localised to the lumbar region, worse with movement and improves with rest. There are no red flag features: no trauma, fever, weight loss, neurological deficits or bowel/bladder dysfunction. Examination shows mechanical back pain only. According to Choosing Wisely Canada, what is the most appropriate management regarding imaging?