Capps v Miller – Case Summary

Capps v Miller

Court of Appeal

Citations: [1989] 1 WLR 839; [1989] 2 All ER 333; [1989] RTR 312; (1989) 133 SJ 1134; [1989] CLY 2536.


The claimant was riding his motorcycle when he collided with the defendant’s car. The defendant was drunk and driving negligently. The claimant had been wearing a helmet, but had not fastened it properly. As a result, it came off as he was falling from the motorbike. The claimant struck his head on the road and suffered severe brain injury. Expert evidence indicated that the claimant would still have been injured if he had worn his helmet properly, but his injuries would not have been as bad. In the High Court, the defendant was held entirely responsible for the injuries. The judge had refused to apply the defence of contributory negligence.

  1. Should the claimant’s damages be reduced for contributory negligence if their lack of care contributed only to the extent of the injuries and not their occurrence?
  2. If so, what should the reduction be?

The Court of Appeal held in favour of the defendant. The claimant’s damages were reduced by 10% to reflect contributory negligence.

This Case is Authority For…

Contributory negligence also applies where the claimant’s lack of care increases the severity of the injury, even if it did not contribute to the underlying accident.

The correct reduction to make where a helmet is improperly fastened in a way which worsens the claimant’s injuries is 10%.


Croom-Johnson LJ disagreed with the other judges on the issue of what reduction should be made. He argued that:

  1. The typical reduction should be around 15% where the injury is worsened by the improperly fastened helmet;
  2. The typical reduction should be around 25% where the injury would have been prevented altogether if the helmet had been fastened properly.

This follows the guidance given in relation to seat-belts in Froom v Butcher [1976] 1 QB 286. It also assumes that the failure to properly fasten a helmet is as bad as failing to wear a helmet altogether. Glidewell and May LJ preferred 10%, since they did not think that the failure to fasten a helmet properly was a blameworthy as failing to wear one altogether.

The judges also clarified that there is no rule preventing the court from making reductions of less than 10%, as the trial judge had wrongly stated.