Here's a study published in Australia in 2011 looking at injury reduction rates based on safety gear. They do a pretty good job of looking into each zone of the body. Most of the results are what you'd expect, i.e., armored gear keeps the severity of your injuries down. The experimental design leaves a little to be desired, especially the sample size and reliance on self-reporting in some cases. Anyway, here's the abstract and link to the full paper:
Motorcycle protective clothing: Protection from injury or just the weather?
Rome et al 2011
Background: Apart from helmets, little is known about the effectiveness of motorcycle
protective clothing in reducing injuries in crashes. The study aimed to quantify the association
between usage of motorcycle clothing and injury in crashes.
Methods: Cross-sectional analytic study. Crashed motorcyclists (n=212, 71% of identified
eligible cases) were recruited through hospitals and motorcycle repair services. Data was
obtained through structured face-to-face interviews.
The main outcome was hospitalization and motorcycle crash-related injury. Poisson regression
was used to estimate relative risk (RR) and 95% confidence intervals for injury adjusting for
potential confounders.
Results: Motorcyclists were significantly less likely to be admitted to hospital if they crashed
wearing motorcycle jackets (RR=0.79, 95% CI: 0.69-0.91), pants (RR=0.49, 95% CI: 0.25-0.94),
or gloves (RR=0.41, 95% CI: 0.26-0.66). When garments included fitted body armour there was
a significantly reduced risk of injury to the upper body (RR=0.77, 95% CI: 0.66-0.89), hands and
wrists (RR=0.55, 95% CI: 0.38-0.81), legs (RR = 0.60, 95% CI: 0.40-0.90), feet and ankles
(RR=0.54, 95% CI: 0.35-0.83). Non-motorcycle boots were also associated with a reduced risk of
injury compared to shoes or joggers (RR=0.46, 95% CI: 0.28-0.75).
No association between use of body armour and risk of fracture injuries was detected. A
substantial proportion of motorcycle designed gloves (25.7%), jackets (29.7%) and pants
(28.1%) were assessed to have failed due to material damage in the crash.
Conclusions: Motorcycle protective clothing is associated with reduced risk and severity of
crash related injury and hospitalization, particularly when fitted with body armour. The
proportion of clothing items that failed under crash conditions indicates a need for improved
quality control. While mandating usage of protective clothing is not recommended,
consideration could be given to providing incentives for usage of protective clothing, such as tax
exemptions for safety gear, health insurance premium reductions and rebates.
