The Veteran's service-connected back scars are painful and warrant a 10 percent rating under DC 7804. The low back disability is also rated at 10 percent, but the TDIU claim remains pending.

The Veteran's low back disability, radiculopathy of the right and left lower extremities, and neck disability are all rated at 40 percent effective January 31, 2020. The claim for TDIU is dismissed.

The Veteran's sleep apnea was rated at 50 percent, but the Board found that it did not meet the criteria for a higher rating due to lack of chronic respiratory failure with carbon dioxide retention or cor pulmonale.,For the left knee injury prior to November 25, 2014, the Veteran received a 10 percent rating based on painful motion. After this date, he was granted a 30 percent rating for limitation of extension and a 20 percent rating for meniscal tear.,Major depressive disorder was rated at 30 percent, which is the maximum available under Diagnostic Code 9434.,Degenerative disc disease (low back disability) was rated at 40 percent, but not higher due to lack of ankylosis or incapacitating episodes of intervertebral disc syndrome.,Erectile dysfunction received a non-compensable rating.

The Board denied the veteran's claims for service connection for a right leg disorder, left foot disorder, and residuals of a right ankle sprain (right foot disorder), as there is no evidence linking these conditions to his military service.

The Board denied the veteran's claims for increased ratings for his service-connected lumbar myositis, psychoneurosis and conversion hysteria, residuals of shrapnel wounds of the left thigh and pelvis with retained foreign bodies and scars, and residuals of shell fragment wounds of the right thigh and left leg. The veteran was also denied entitlement to a total disability rating based on individual unemployability due to service-connected disabilities.