Howell Test Fixture
Optional for Howell SkiBindings — but suggested.
Available now.
Howell Test Fixture (sm) validates, demonstrates and calibrates the unique settings for ACL-friendly Howell SkiBindings with additional, lateral-heel release.
Photo 1. ‘Howell Test Fixture bolted to ski-tuning bench. ‘Bench not included.
Photo 2. ‘Fixture firmly holding an alpine ski-boot.
Photo 3. The ski is held only by the binding; the binding is held only by the boot; the boot is rigidly held by the fixture.
Photo 4. (Beta) Howell SkiBindings release setting recommendations chart for all 3 modes of release — torsion-about the long-axis of the tibia for lateral-toe release settings; forward-bending-moment for forward-heel settings; and abduction-moment for lateral-heel settings.
Photo 5. Current Howell SkiBindings release setting recommendations chart for verifying lateral-heel settings — by testing the complete ski-boot-binding system (see footnotes on chart).
Made of 303 stainless-steel — the Howell Test Fixture is one piece, welded. Two stainless-steel micro-fiddle blocks and two high-strength sailing lines are included and pre-assembled. The bench and bolts for mounting the fixture to a bench are not included. Wooden shipping container and detailed instructions are included. Total shipping weight including wooden shipping container: 11 pounds. FOB Québec, Canada.
Howell Test Fixture and its test-method rely on a combination of …
1— … industry standardized recommended settings — DIN / ISO 8061 — for the ordinary 2-mode functions of Howell SkiBindings — lateral-toe and forward-heel;
2— … Howell SkiBindings pre-set for ordinary 2-mode function — including calibrated measurement of the recommended torsional release torque setting from point #1;
3— … the test-fixture’s ability to solidly-hold any ski-boot on just about any sturdy bench — to allow lateral-force to be user-applied to the ski that is held only by its binding.
( Boot-sole length is automatically-factored.)
In this way, the special lateral-heel settings of Howell SkiBindings are tested to compare with the expected-settings.
The measurement-metric that is specified to test the lateral-heel settings is the position of the applied-abduction-force on the ski. The special positions on the ski that are specified by Howell SkiBindings are conceptually-based on matching the actual vertical-distance from the base of the ski at the projected-axis of the tibia to the center of a given skier’s knee (‘abduction lever-arm’) — matched to the same distance between the mid-sole-mark on the mounted-ski-boot to a ‘zone’ on the back-half of the ski (the off-set between the boot’s mid-sole-mark and the projected-axis of the tibia is factored into Howell-recommended setting-specifications). We call the special zone on the back-section of the ski, the ‘Transition-Zone’. (The size of the specified Transition-Zone represents the average expected friction within the ski-boot-binding system.) It’s generally not practical to measure the distance from the base of the ski to the center of a given skier’s knee. Therefore, we provide a special chart that estimates the length of the abduction-lever-arm, which estimate also represents the position of the Transition-Zone on the ski — based on skier weight, gender, average boot-sole thickness under the heel, and the stand-height of Howell SkiBindings — including a tolerance, to form the size of the Transition-Zone’. ‘See special BETA chart in photo gallery.
A margin-of-release is imbedded into the Howell-setting-specifications based upon the ‘remaining-distance’ from the boot’s mid-sole-mark to the virtual-pivot that is formed by the lateral-heel release-binding’s toe-cup (that’s not a typo — that’s right, the toe-cup). This ‘remaining-distance’ automatically-factors variation in boot-sole length to scale the margin-of-release in the lateral-heel mode of release. Again, see special BETA chart in photo gallery for specifications.
Howell-recommended lateral-heel release-setting specifications apply ONLY to Howell SkiBindings.
Testing to validate lateral-heel release settings can be completed in minutes.
Testing should take place every 30 skiing-days or before the beginning of each ski season, which ever comes first.
‘Metallic-foot is fully-integrated.
Howell Test Fixture is intended for ski shops — but can be purchased and used by any skier or ski shop.
(( ‘Also useful for demonstrating how ordinary 2-mode alpine bindings have no possibility of providing ACL or MCL friendly skiing at any setting.))
Detailed Test Method:
(1) All three visual release indicators on left and right Howell SkiBindings should be ‘pre-set’ according to the ‘Howell SkiBindings Recommended Release Setting Chart’ — which lateral-toe and forward-heel pre-settings conform to DIN/ISO 9462 and ISO 8061 for ordinary 2-mode bindings. See BETA chart in photo gallery (BETA — and not for use with any ski-bindings other than Howell SkiBindings. This beta chart will be updated prior to October, 2023). No standards apply to Howell SkiBindings lateral-heel release settings because this is an additional mode of release that is not provided (yet) by other alpine ski-binding companies. Boots must conform to ISO 5355 — the main international alpine ski boot standard. Boots must not have metal inserts for ‘pin-bindings’ (‘pin-bindings’ are hardly “tech” and can cause horrific tibia-tuberosity fracture).
(2) Mount the Howell Test Fixture to a sturdy bench.
(3) Firmly affix the ski-boot to the Howell Test Fixture by cinching the 2 high-tech sailing lines with the micro-fiddle blocks as depicted in the above photos.
(4) (( 4.a) Measure the distance from the base of the ski to the center of the knee — measure along the side of the lower leg — then transfer that same distance from the boot’s mid-sole-mark to the back-half of the ski and add +/- 4cm to mark a ‘transition-zone’ on the ski. ))
— OR —
(4.b) Select the recommended ‘Transition-Zone’ from the Howell Lateral-Heel Release Settings Chart. ‘See photo gallery. (BETA — and not for use with any ski-bindings other than Howell SkiBindings. This beta chart will be updated prior to October, 2023).
If both ways of generating a Transition-Zone are deployed, use the longer distance.
(5) Mark both end-points (the +/-4cm range) of the Transition-Zone on the ski.
(6) Attach the ski to the boot that is securely held by the Howell Test Fixture.
(7) Semi-loosely secure the ski at 2-points through the use of your own ‘limiter-lines’ to block the range of motion of the released ski to prevent injury to the person conducting the tests.
(8) Apply abduction (lateral) force to the inside-edge of the ski as follows:
(8.a) Apply lateral force with a gloved-hand to the ski at a point located 5 cm greater-than the Transition-Zone — to cause lateral-toe release;
(8.b) Apply lateral-force with a gloved hand to the ski at a point located 5 cm less-than the Transition-Zone — to cause lateral-heel release.
(9) If lateral-toe release AND lateral-heel release do not take place as described in points #8.a AND #8.b (both conditions) do NOT change the lateral-toe release-settings. Do not change the forward release-settings. Do not change the forward-pressure settings. Change ONLY the special additional lateral-heel release settings in Howell SkiBindings — provided, however, that no change in the lateral-heel release-indicator setting is greater than 2 lateral-heel release-indicator numbers.
(10) If a change of more than 2 lateral-heel release-indicator numbers is required to cause the function that is specified in points #8.a AND #8.b — a list of ‘Troubleshooting Actions’ is provided by Howell SkiBindings to correct the function of the ski-boot-binding system. (The few problems that arise are typically with the boot-interface ... and can be easily resolved ... for example, by removing mold-flashings on the boot sole.)
(11) If, after applying the Troubleshooting Actions, the functions in points #8.a AND #8.b are still not occurring — the binding, the boot, or both — are defective and/or incompatible and should be returned to Howell SkiBindings (and/or to the respective ski-boot company) for warranty replacement.
In the unlikely adverse-scenario of point #11 — Howell SkiBindings are most likely remaining in compliance with ordinary 2-mode alpine binding function according to DIN / ISO 9462: ordinary 2-mode testing procedures can verify compliance. However — ACL, MCL, meniscus, tibial-plateau friendly skiing may be adversely compromised, just as it is always compromised with all ordinary 2-mode alpine bindings.
Using the Howell Test Fixture is simple and fast once the above methods are understood.
Use of the Howell Test Fixture is optional with Howell SkiBindings — but suggested.
Available now.
Biomechanical Proof
Howell Test Fixture is based on 20-years of intensively focused biomechanical research conducted by Rick Howell — peer-reviewed and approved by bona fide scientific committees at major international orthopedic / engineering / skiing safety conferences ...
International Society for Skiing Safety (ISSS) Pontresina, Switzerland, 2003 (presented by University of Montréal biomechanical engineering researchers based on a 2001 grant-application promulgated by Rick Howell (Canadian federal government IRAP grant: outcome published in the Journal of Medicine and Science in Sports and Fitness). All other venues listed below involve scientific presentations investigated and presented by Rick Howell ) ...
... ISSS-Niigata, Japan, 2005; ISSS-Aviemore, Scotland, 2007; ISSS-Bariloche, Argentina, 2013; ISSS-Cortina, Italy, 2015; ISSS-Innsbruck, Austria, 2017; ISSS-Squaw Valley, USA, 2019; ISSS-Serre Chevalier, France, 2022.
SITEMSH (International Medical Society for Skiing Safety [Société Internationale de Traumatologie et Médecine des Sports d’Hiver]) SITEMSH-Flachau, Austria, 2014; SITEMSH-Inawashiro, Japan, 2016; SITEMSH-Barcelona, Spain, 2018; SITEMSH-Serre Chevalier, France, 2022.
International Olympic Committee (IOC) World Conference on Prevention of Injury and Illness in Sport, Monaco, 2017, and again in Monaco, 2021;
European Society for Knee Surgery, Arthroscopy and Sports Traumatology (ESSKA), Barcelona, Spain, 2016 — peer-reviewed, approved, and published in British Journal of Sports Medicine; and ESSKA-Virtual (originally organized to be held in Madrid, Spain — but became virtual due to the pandemic), May, 2021.
International Society for Science in Skiing (ICSS), Voukatti, Finland, 2019.
Biomechanical Engineering-Technology
The biomechanical engineering-technology behind ACL-Friendly Howell SkiBindings and Howell-specified lateral-heel settings is simple.
During ‘Slip-Catch’ or ‘Phantom Foot’ injury-events with shaped-skis, large abduction-moments are generated when the center of the forces that act between the snow and a shaped-ski enter the shaped-ski, laterally, close-behind the projected-axis of the tibia. Shaped-skis do not slip at one end — thus, rotation about the tibia-axis is minimal while lateral-movement of the shaped-ski (relative to the position of the knee) is maximal. The center of the abduction-forces that enters a shaped-ski is not sensed by ordinary 2-mode alpine ski bindings because it is located close to the tibia-axis: there is no effective lever-arm within an ordinary 2-mode binding to produce ordinary 2-mode release. There’s no possibility of release before ACL-rupture, irrespectively of the release-settings: a child’s toe-setting would still prevent release before ACL-rupture. This phenomena occurs because the same centrally-located abduction-force that enters the ski at the ski/snow interface, acts over the length of the lower-leg (in-part, the ‘abduction-lever-arm’) to produce a large abduction-moment across the ACL, MCL, meniscus, tibial-plateau and femoral condoles — to cause severe traumatic injury to these tissues …
... unless …
... a special binding with additional, non-pre-releasing, lateral-heel release (also with special settings for lateral-heel release — see above) reads and reacts to the forces that are generated by shaped-skis during highly-loaded Slip-Catch or Phantom-Foot events. ‘A 3-mode binding.
HOWEVER — AN IMPORTANT HOWEVER — special bindings with additional lateral-heel release and specially-tuned lateral-heel release-settings MUST NOT pre-release. Howell SkiBindings uniquely provide key know-how and key technology to block pre-release without high settings in all 3-modes of release. Anti-pre-release is uniquely and decisively provided by Howell SkiBindings by ‘decoupling’ of each of the 3-modes of release (decoupling each mode from the others) AND by decoupling each mode of release from skiing-control modes that do not need release (edging). See ‘Retention’ and ‘Edge Control’ sub-links in the Menu. Each of the 3 modes of release in Howell SkiBindings is a separate system (3 separate springs; 3 separate cams): each of the 3 modes of release function without being adversely effected by each other. Further, all 3 separate release cams in Howell SkiBindings are widely-off-set knuckle-joints that filter-out the compressive forces caused by ski-flex from the release-functions. Ski-flex can cause pre-release in all other brands of bindings — including in newly-announced soon-forthcoming competitors — unless they have highly elevated settings: highly elevated settings block necessary release! Still further, each release-cam in Howell SkiBindings rotates in a way that is uninfluenced by edging. Other bindings do not provide all of these combined features and functions because Howell know-how has refined them during 4 decades of research, development, testing, testing and … testing. Lastly, the secret sauce is that Howell SkiBindings accomplishes all of these combined functions, simply. ‘Simple’ importantly translates to durable and reliable. All Howell-developed products (5 worldwide #1-sellers) embody the hallmark of robust-function within simple-execution.
Biomechanical Engineering-Technology
The biomechanical engineering-technology behind ACL-Friendly Howell SkiBindings and Howell-specified lateral-heel settings is simple.
During ‘Slip-Catch’ or ‘Phantom Foot’ injury-events with shaped-skis, large abduction-moments are generated when the center of the forces that act between the snow and a shaped-ski enter the shaped-ski, laterally, close-behind the projected-axis of the tibia. Shaped-skis do not slip at one end — thus, rotation about the tibia-axis is minimal while lateral-movement of the shaped-ski (relative to the position of the knee) is maximal. The center of the abduction-forces that enters a shaped-ski is not sensed by ordinary 2-mode alpine ski bindings because it is located close to the tibia-axis: there is no effective lever-arm within an ordinary 2-mode binding to produce ordinary 2-mode release. There’s no possibility of release before ACL-rupture, irrespectively of the release-settings: a child’s toe-setting would still prevent release before ACL-rupture. This phenomena occurs because the same centrally-located abduction-force that enters the ski at the ski/snow interface, acts over the length of the lower-leg (in-part, the ‘abduction-lever-arm’) to produce a large abduction-moment across the ACL, MCL, meniscus, tibial-plateau and femoral condoles — to cause severe traumatic injury to these tissues …
... unless …
... a special binding with additional, non-pre-releasing, lateral-heel release (also with special settings for lateral-heel release — see above) reads and reacts to the abduction-loads that are generated by shaped-skis during highly-loaded Slip-Catch or Phantom-Foot events.
HOWEVER — AN IMPORTANT HOWEVER — special bindings with additional lateral-heel release and specially-tuned lateral-heel release-settings MUST NOT pre-release. Howell SkiBindings uniquely provide key know-how and key technology to block pre-release without high settings in all 3-modes of release. Anti-pre-release is uniquely and decisively provided by Howell SkiBindings by ‘decoupling’ of each of the 3-modes of release (decoupling each mode from the others) — AND by decoupling each mode of release from skiing-control modes that do not need release (edging). See ‘Retention’ and ‘Edge Control’ sub-links in the Menu. Each of the 3 modes of release in Howell SkiBindings is a separate system (3 separate springs; 3 separate cams): each of the 3 modes of release function without being adversely effected by each other. Further, all 3 release cams in Howell SkiBindings are widely-off-set knuckle-joints that filter-out the compressive forces caused by ski-flex — ‘filter-out’ from the release-functions. Still further, each release-cam rotates in a way that is uninfluenced by edging. Other bindings do not provide all of these combined features and functions because Howell know-how has refined them during 4 decades of research, development, testing, testing and … testing. Lastly, the secret sauce is that Howell SkiBindings accomplishes all of these combined functions, simply. ‘Simple’ importantly translates to durable and reliable. All Howell-developed products (5 worldwide #1-sellers) embody the hallmark of robust-function within simple-execution.
100% 303 stainless steel: 7.75-pounds.
Shipping weight: 11-pounds.
Lifetime Limited Warranty.
Available now.
Howell SkiBindings, Inc.
P.O. Box 1274, Stowe, Vermont 05672 USA
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‘Howell Test Fixture’ (sm) is a Service Mark of Howell SkiBindings (sm).
Copyright © 2022 by Howell SkiBindings, Inc.; Howell Product Development Holding, Inc.; and by Rick Howell. All rights reserved.
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