Rocker-soled Shoe

  • Designed to roll or rock a foot forward when walking
  • Rocks/rolls forward during the stance phase of gait
  • The thicker sole has to have a degree of rigidity to limit bending
  • Can incorporate specific curves at different parts of the shoe
    • 2 curved rocker
    • 3 curved rocker
    • Radius from ankle centre, hip centre, knee centre


  • They are used to change a specific biomechanical pattern during walking

    • Used to change the kinematic pattern, e.g:

      • limit movement of the 1st MTP joint
      • reduce ankle/knee range of motion
    • Used to change kinetic (moment pattern) and the ankle, knee or hip

      • Result in a change in the centre of pressure and/or direction of the ground reaction force vector
    • Used to change the pressure distribution under the foot (plantar pressure distribution)

    • Used to change muscle activation patterns

Other possible effects (claimed by manufacturers):

  • Decreased metabolic energy consumption
  • Balance training
  • Improving overall body posture
  • Increasing muscle strength
  • These have not been backed up by clinical assessments!

Clinical Management:

  • Used to manage a range of clinical conditions e.g:
    • Osteoarthritis of the foot
    • Intermittent claudication
    • Plantar fascilitis

Foot Ulceration in Diabetes

  • Patients with diabetes are susceptible to:

    • Plantar ulcers (caused by increased pressure)

      • Pressures above 200 KPa can cause ulceration (Owings et al. (2009))
    • Heel ulcers (caused by increased pressure)

    • Dorsal ulcers (caused by poor fit)

    • Infection/bacterial growth (caused by increased humidity/temperature)

Research Designs for Optimising Footwear Design

  • Can consider 3 levels of research questions

    • Level 1: Questions to describe phenomena

      • theoretical or conceptual material but nothing known empirically
      • lead to descriptive designs, more complex research
    • Level 2: Questions which explore relationships

      • study relationships among phenomena which have already been studied at descriptive level
    • Level 3: Questions which test knowledge about cause-effect

      • contain predictive statements about what will happen to one variable on the basis of knowing another
      • manipulate 1 variable to understand the effect it has on another
  • Operationalisation: reducing phenomena to a number in order to carry out statistical analysis

    • if the outcome is not chosen appropriately, the study has limited validity

Example: - Level 1: Do patients use their footwear at home - Level 2: Relationship between footwear use and x muscle strength - Level 3: Effect of changing footwear on x muscle strength

  • Rocker profile: number of parameters e.g.

    • rocker angle for curved rocker shoe
    • apex position
    • rocker axis
  • Repeated measures design:

    • all people exposed to different conditions
    • e.g. testing a number of different shoe designs
      • in-shoe pressure sensor used to measure plantar pressure to quantify data
      • calculate pressure curve for sensors at a given time
      • locate area of peak pressure

Purpose of footwear for people with diabetes

  • Elevated plantar pressure is a known risk factor for ulceration
  • Footwear needs to be aesthetically pleasing as well as clinically effective

  • Types of footwear for patients with diabetes

    • extra depth shoes
    • flexible shoes
    • traditional rocker shoes
    • curved rocker shoes
  • Acceptability of footwear for patients

    • influenced by:

      • relative risk of adverse health outcome
      • previous experience with adverse health outcome
    • Prevention is better than treatment

      • better to target those who are at moderate risk with acceptable footwear choice
    • Manufacturing trade-off with outside geometry to create specific rocker

    • If we want to increase rocker angle, have to have a thicker outsole

      • thicker outsole = more effective
      • But less favourable to patients

Curved Rocker shoe: - Four footwear features: - Rocker angle - Apex position - Apex angle - Sole stiffness

  • Typical shoe:

    • apex angle of 55% of shoe length
    • rocker angle of 10 degrees
    • rocker axis aligned with metatarsal break
  • Need a control study varying each of the design features to see effect on the foot