Customized rocker sole constructions German guidelines to improve results in daily practice Stief, Thomas Registered Association for the Encouragement of Research and Education Management in Orthopedic Footwear Technology Germany, Hannover Germany Orthopedic footwear modifications Background no internationally accepted terminology and method exists to describe the devices used in the field of footwear modifications, like rocker soles Chapman et al. 2013 this creates problems for clinicians, manufacturers and researchers attempting to compare the treatments used in different countries and their outcomes the German guideline, e.g. the medical aids list, specifies the clinical objectives for the use of these devices and describes their functions and their components 2 1
Orthopedic footwear modifications Background The aim of the talk is to present the German guidelines for footwear modifications, e.g. rocker sole constructions, and to discuss the international differences of the construction details and the used terminology to improve the results in daily practice. 3 Medical aids list Background approx. 90 % of the population in Germany are members of statutory health insurance all of the members are entitled to receive benefits to maintain and restore their health or to improve their state of health most sections of the health care system are shaped by self government, via contracts that are concluded with the health care providers, not by law as a matter of principle, costs for medical aids can only be met by statutory health insurance if the products are included in the list of aids the list is not binding in the legal sense 4 2
Medical aids list Background products are included in the list of aids at the request of the manufacturers (or of third parties empowered by them), if they have specific characteristics and meet certain quality criteria products that are available on the market are allocated to various product groups according to their fields of deployment the list guarantees that medical care is provided as needed, that its quality is assured and that it is provided regularly, and that it corresponds to the medical state of the art (section 70 of Book Five of the Social Code) 5 Medical aids list The formation of a product group product group, e.g. 31 orthopedic footwear region of application, e.g. 03 foot sub product groups, e.g. 04 orthopedic footwear modifications (requirements acc. to section 139 of Book Five of the Social Code) product type with definition and with scope of indications, e.g. 2 modifications to the sole product with individual descriptions, e.g. 000 rocker sole modifications 6 3
Rocker sole modifications rocker soles are one of the most commonly prescribed footwear modifications basic function: to rock the foot during stance phase, without bending the foot and shoe the type of the rocker sole varies with the clinical treatment objectives, related to patient's individual foot problem the general biomechanical effects compensation of lost motion in the foot or ankle joints related to pain, deformity, or stiffness, resulting in an overall improvement in gait and relieving bending of the joints and relieving pressure on some area of the plantar tissues (Janisse 1995, Baumgartner et al. 2013) 7 General construction details for all individualized rocker soles 1. apex a. position b. angle depending on the position of MTP Joint (MTP I and MTP V) 2. rocker shape curved rocker, so called classical rocker are not used progressive shape from the apex position to the shoe tip elliptic shape 1. 8 2. 1. 4
General construction details for all individualized rocker soles 3. distance between the tip of the shoe and the ground the rocker angle is not used in Germany, cause of the curved rocker shape! individualized construction, by using the patient s footprint as a guide 3. 9 General construction details for all individualized rocker soles further details: 4. the height of the heel must also be adapted 5. the midstance length of the shoe must ensure a balanced standing and walking material properties of the rocker bar EVA with SH 50A SH 60 if necessary: a compensating rocker sole for the contralateral side, to achieve symmetrical gait 10 5
Types of individualized rocker soles forefoot (toe only) rocker sole forefoot (toe only) rocker sole with cushioning for metatarsal region forefoot (toe only) rocker sole with deepening for the distal phalanx I midfoot rocker sole heel to toe rocker sole (rocker bottom sole) tip rocker sole (triangular forefoot rocker) 11 Forefoot (toe only) rocker sole indications hallux limitus and hallux rigidus hallux valgus rheumatoid arthritis at MTP I treatment objectives facilitation the rollover of the foot during gait reduction of forefoot stress during toe off protection of the metatarsal heads reduction of bending stress at the metatarsophalangeal joints 12 6
Forefoot (toe only) rocker sole construction details apex position: 10 mm proximal to MTP I and MTP V angle: depending on the line between the MTP I and MTP V distance between the tip of the shoe and the ground: 15 mm individualized construction 13 Forefoot (toe only) rocker sole Biomechanics of the MTP joints, e.g. MTP I walking without modification d M MTP F B 14 7
Forefoot (toe only) rocker sole Biomechanics of the MTP joints, e.g. MTP I walking without modification d M MTP F B 15 Forefoot (toe only) rocker sole Biomechanics of the MTP joints, e.g. MTP I walking with forefoot (toe only) rocker sole d F B M MTP 16 8
Forefoot (toe only) rocker sole Biomechanics of the MTP joints, e.g. MTP I walking with forefoot (toe only) rocker sole d M MTP F B 17 Heel to toe rocker (rocker bottom sole) Biomechanics of the MTP joints, e.g. MTP I torque at terminal stance without modification with forefoot (toe only) rocker sole 18 9
Forefoot (toe only) rocker sole with a cushioning for metatarsal region indications painful hallux rigidus rheumatoid arthritis at MTP I treatment objectives further reduction of MTP I stress during toe off excessive relieve of plantar pressure at distal phalanx of the hallux construction details see also: forefoot (toe only) rocker sole the rocker bar has been omitted at the distal phalanx region of the hallux Walther et al. 2013 19 Forefoot (toe only) rocker sole with a cushioning for metatarsal region indications metatarsalgia (ball of foot pain) rigid pes transversoplanus rheumatoid arthritis treatment objectives to reduce the plantar load on the metatarsal region to reduce pain of the metatarsal heads 20 10
Forefoot (toe only) rocker sole with a cushioning for metatarsal region construction details see also: forefoot (toe only) rocker sole inner sole and the rocker bar have been omitted (funnel shaped) at the metatarsal region and replaced by cushioning material (Shore A25 to A35) the shape of the deepening depends on the localization of the problems finally covered with a thin sole important: to prevent metatarsal heads from dropping down, a metatarsal support is indicated! normally used with a metatarsal support! 21 Midfoot rocker sole indications several degenerative and painful diseases at: the metatarsal and tarsal joints and the ankle joint forefoot amputations treatment objectives intend to aid propulsion during pre swing reduction of bending stress by shortening the forefoot lever arm pain reduction 22 11
Midfoot rocker sole construction details apex position: > 15 mm proximal to MTP I and MTP V angle: depending on the line between the MTP I and MTP V distance between the tip of the shoe and the ground: > 20 mm 23 Midfoot rocker sole Biomechanics of the ankle joint walking without modification d M ankle F B 24 12
Midfoot rocker sole Biomechanics of the ankle joint walking with midfoot rocker sole d M ankle F B 25 Midfoot rocker sole Biomechanics of the ankle joint torque at terminal stance without modification modified with midfoot rocker sole 26 13
Heel to toe rocker (rocker bottom sole) indications diabetic foot syndrome excessive degenerative and painful diseases at: the tarsal joints and the ankle joint midfoot amputations treatment objectives decrease the mid and rear foot, as well as ankle joint stress from the initial contact to terminal stance phase reduction of the ankle motion 27 Heel to toe rocker (rocker bottom sole) construction details apex (midfoot) position: > 20 mm proximal to MTP I and MTP V angle: depending on the line between the MTP I and MTP V distance between the tip of the shoe and the ground: > 25 mm highly convex rocker soles roll more quickly 28 14
Heel to toe rocker (rocker bottom sole) Biomechanics of the ankle joint torque at initial contact without modification modified with heel to toe rocker M ankle M ankle 29 Heel to toe rocker (rocker bottom sole) Biomechanics of the ankle joint torque at terminal stance without modification modified with heel to toe rocker M ankle M ankle 30 15
Tip rocker indications knee joint instability treatment objectives promote balanced standing and walking control knee joint instability control the motion of the knee joint 31 Tip rocker construction details apex position: distal to DIP I and DIP V angle: depending on the line between the MTP I and MTP V distance between the tip of the shoe and the ground: 10 mm may combined with little heel pitch to give more stabilization to the knee 32 16
Individualized rocker soles Evidence for reducing in shoe pressure the rocker outsole is one of the most effective footwear design (Hutchins et al., 2009a) the apex position may need to be individually adjusted to maximize offloading (Van Schie et al. 2000) reduce plantar stress, like plantar pressure in patients with Diabetic Foot Syndrome (Chapman et al. 2013) 33 Individualized rocker soles Evidence bending stress could be significantly reduced at MTP I and MTP V by using a customized rocker sole construction compared to a neutral shoe and a control condition. (Vogelbusch et al. 2013) 34 17
International Standard for Orthopedic Footwear in process the new ISO XXX Standard establishes a method of classifying and describing the devices that are used in the field of orthopedic footwear it does not describe the materials or manufacturing methods used for their fabrication 35 Further information: stief@bifo ost.de Stief, T.: Gemeinsam Forschen für die tägliche Praxis der OST 4/10/2016 36 http://kunstaufraeumen.ch/shop/shop_htm_files/92.png 18