Final answer:
The athletic trainer should recommend that the athlete decrease activity and use ice massage three times a day to manage symptoms of tendinitis. Repeated motions have likely caused the condition, and rest along with ice therapy will help reduce inflammation and avoid further injury.
Step-by-step explanation:
The athlete complaining of pain with repetitive wrist motions and swelling over the extensor carpi radialis longus is likely suffering from tendinitis, an inflammation of the tendon caused by overuse. In this scenario, the athletic trainer should recommend that the athlete decrease activity and use ice massage three times a day to manage the condition. This recommendation aligns with standard first aid for a muscle strain and tendinitis, which includes the acronym PRICE (protection, rest, ice, compression, and elevation), and the use of NSAIDs (non-steroidal anti-inflammatory medication) to relieve pain and reduce swelling.
Exercises and increased activity may exacerbate the condition, potentially leading to further injury and a longer recovery period. Hence, option d, which advises decreasing activity and using ice massage, would be the most immediate and appropriate action to manage the symptoms and promote healing.