OPINION
EASTAUGH, Justice.I. INTRODUCTION
We must decide whether it was error to dismiss Edward Metcalfs superior court workers’ compensation appeal under authority of Appellate Rule 511.5 because Metcalf failed to timely file his opening superior court brief. We reverse.
II. FACTS AND PROCEEDINGS
Metcalf appealed from the September 29, 1995, decision- and order of the Alaska Workers’ Compensation Board. His opening superior court brief was originally due February 1, 1996. Metcalf timely moved for a six-month extension of time in which to submit his opening brief; if granted, his motion would have extended the filing date to August 1, 1996. Superior Court Judge Dana Fabe granted Metcalf a ninety-day extension. His brief was thus due May 1. Metcalf, who was pro se, moved to “amend” the extension order to obtain the full six months he had requested. Superior Court Judge John Reese denied the motion to “amend” and later denied Metcalfs further motion for permission to file his brief July 81. On May 28 the appellees moved pursuant to Appellate Rule 511.5 to dismiss Metcalfs appeal because he had not filed his brief.1
On July 31 Metcalf tendered his opening brief to the superior court, where it was lodged.
On August 15 Judge Reese granted the appellees’ motion to dismiss; he later denied Metcalfs timely motion for reconsideration. Alaska R. Civ. P. 77(k)(4).
Metcalf alleged that permanent disability caused by a brain concussion (suffered in the industrial accident which is the subject of his workers’ compensation claim) justified extending the time in which to file his opening brief. He also alleged that he has to spend eighteen hours a day in bed or resting and can be up for only three two-hour periods daily without getting bad headaches, that the stress of preparing one of his supreme court briefs permanently disabled his digestive system and gave him a skin condition, and that stress caused by intensive work on his appeal briefs caused internal bleeding in his digestive system. There is substantial doubt about Metcalfs credibility, given findings by the Alaska Workers’ Compensation Board in its September 29, 1995, decision and order that he is “not a credible witness” and that he “could work for more than six hours in a day if he wanted.” Nonetheless, the validity *1025of these findings was one of the topics Met-calf attempted to address in his superior court appeal. This topic was actually discussed in the opening brief he lodged with the superior court July 31,1996.2
III. DISCUSSION
This court reviews a superior court’s dismissal of an appeal from an administrative agency decision for lack of prosecution under Appellate Rule 511.5 for abuse of discretion. Geczy v. State, Dep’t of Natural Resources, 924 P.2d 103, 104 (Alaska 1996) (citing Cowitz v. Alaska Workers’ Compensation Bd., 721 P.2d 635, 638 n. 2 (Alaska 1986)). An abuse of discretion will be found only when a decision is “arbitrary, capricious, manifestly unreasonable, or ... stems from an improper motive.” Sheehan v. University of Alaska, 700 P.2d 1295, 1297 (Alaska 1985) (citations omitted).
We conclude that it was an abuse of discretion to grant the motion to dismiss under Appellate Rule 511.5 despite Metcalfs failure to file his brief timely. Even though Metcalf unquestionably failed to timely file the brief per the controlling extension order, the superior court had actually received the brief more than two weeks before it entered the dismissal order. The excuse tendered by Metcalf — his continuing work-related disability — was interrelated with substantive appellate issues he was attempting to raise. If it was true that he had suffered a permanent disability and that he slept eighteen hours a day, substantial justification for further extension of time was demonstrated by this pro se litigant. We also note that Felec Services and Cigna Insurance Companies, in moving to dismiss, made no showing that they would be prejudiced by the filing delay. For example, appellees did not demonstrate that the delay would hamper their ability to controvert Metcalfs claim on its merits. Given that the brief had already been lodged and that appellees demonstrated no prejudice, the harsh remedy of dismissal could be justified only if there had been some controlling principle, such as a need to punish the wrongdoer, deter like conduct, preserve the integrity of the fact finding process, or protect the dignity of the court. The superior court identified no such justification. The failure to abide by the court’s extension order might well have justified imposition of some sanction, and had appellees demonstrated that they incurred unnecessary costs, some appropriate remedy might have been fashioned. Those circumstances themselves, however, would not justify complete dismissal of Metcalfs appeal. We also note that there is no reason to think delay worked in Metcalfs favor, such that only dismissal could prevent Metcalf from using delay to his benefit. The record does not suggest that the court considered, and rejected as ineffective, any less extreme sanction or remedy.3 Cf. Underwriters at Lloyd’s London v. Narrows, 846 P.2d 118 (Alaska 1993) (setting aside default judgment imposed as sanction for defendant’s discovery violation where the trial court failed to consider the effectiveness of any lesser sanction).
IV. CONCLUSION
For these reasons, the order of dismissal is VACATED and the matter is REMANDED to the superior court for further proceedings. This court’s order of February 19,1997, staying the superior court’s consideration of the cross-appeal, is VACATED.
FABE, J., not participating.. Alaska Rule of Appellate Procedure 511.5 provides:
(a)If an appellant or an appellant’s counsel fails to comply with these rules, the clerk shall notify the appellant and the appellant's counsel in writing that the appeal will be dismissed for want of prosecution unless the appellant remedies the default within 14 days after the date of notification, time to be computed in accordance with Rule 502(c). If the appellant fails to comply within the 14-day period, the clerk shall issue an order dismissing the appeal for want of prosecution. In no case, except by order of the court on a motion to reinstate the appeal, shall the appellant be entitled to remedy the default after the appeal has been dismissed under this rule.
(b) The dismissal of an appeal under subsection (a) shall not limit the authority of the court to impose monetary sanctions under Rule 510.
(c) The court may, upon motion of a party or its own motion, dismiss an appeal for failure to comply with these rules, whether or not prior notice of default has been given.
Appellate Rule 511.5 is made applicable to superior court appeals by Appellate Rule 606(a).
. Because there is a pending superior court cross-appeal, we considered Metcalf's appeal on an expedited basis. We stayed the superior court cross-appeal pending resolution of Metcalf’s appeal in this court. We are ruling on the basis of the record below, including the appellees’ superi- or court motion to dismiss, their opposition to Metcalf’s supreme court motion to docket this appeal, and their opposition to Metcalf’s motion for full court reconsideration of a single justice order denying Metcalf's motion to docket this appeal.
. One such remedy might have been accelerating or limiting any oral argument, or, in the event Metcalf prevailed, denying him costs. The potential ineffectiveness of other remedies is mirrored in the ineffectiveness of dismissal: Met-calf's exercise of his right to appeal the dismissal has substantially added to the delay. This case would be closer to final resolution if the superior court had accepted Metcalf’s brief and considered the appeal and cross-appeal on their merits.