Appeal by carrier and employer from an award of disability compensation. Appellants raise the issues of accident and causal relation. Claimant sustained an accidental injury to his right leg while working for the same employer on May 28, 1945. He was disabled for about eight weeks and compensation was awarded and paid, and the case was closed on May 20, 1946. Claimant went back to work and continued to work although he felt pain in his back and right leg and numbness in his legs. Claimant testified that he sustained a second accident on December 23,1956, when he slipped on some rubbish on the floor of the employer’s warehouse and fell backward on his back and injured his back. He testified that he reported this accident to his foreman. This is disputed. There is medical evidence in the record that claimant had a pre-existing arachnoiditis which was aggravated and activated by the accident of December 23, 1956, causing his disability. Appellants attack claimant’s credibility and attack the medical testimony because it is based on the truth of claimant’s testimony. They characterize the testimony of one doctor as “ unconvincing ”. However, it is in the record and apparently was convincing to the -board. Of course the question of claimant’s credibility and the determination of disputed questions of fact were exclusively within the province of the board. We may not say as a matter of law that the evidence supporting the award is not substantial. Award unanimously affirmed, with costs to the Workmen’s Compensation Board. Present — Bergan, P. J., Coon, Gibson, Herlihy and Reynolds, JJ.