Lucas Grossi (photos: A1 need profile photo)

 

• BKA. Left Leg

• Riding for 16 years

• Regular Foot

• Stance: R +15°, L -3°

 

 

Foot (photos: B1)

 

• The foot is an Axtion® foot by Otto Bock, which is a low to moderate activity foot.

• Lucas says “a stiffer low/moderate activity foot works better for riding because there is less rebound energy returned from the foot on toe-side turns.” This helps lock the edge into a carve and doesn’t bounce a rider off of their edge mid carve.

B1, foot-pylon

 

 

Pylon and Pyramid System (photo: C1)

 

• Aluminum stock pylon with a two pyramid system

• The aluminum prevents torsional twisting of the pylon. The stock carbon-fiber pylon can torsionally twist at higher level riding reducing stability and turn control. Although, some riders prefer some torsional rotation.

• Lucas set the walking alignment then epoxied pyramid adapters to the pylon. This also eliminates twisting of pylon, helping increase control of a turn, but more importantly, it reduces the chance of injury from pylon twisting out of alignment between socket and board during riding.

C1, Pylon

 

 

Pylon Ankle Sheath (photo: D1)

 

• Built from medium weight foam, sheathed in duct tape and shaped like a chin. It fills in the gap between boot and pylon, increasing control by preventing ankle slop during your shred-fest. Cosmetic liners/pylon sheath serve the same purpose.

D1, Pylon Sheath on Pylon

 

 

Socket (photo: E1)

 

• Made from carbon fiber

• Note the coke bottle shape. This shape keeps knee brace from moving, sliding, or twisting, again increasing control and reducing injury.

E1, Socket-Coke Bottle

 

 

Liner and Sleeve (photo: F1)

 

• On right (white) is a 6mm Alps Easy Liner® without a pin. This goes over residual limb. (Note – Stump shape affects attachment system. Lucas’s fibula is longer than his tibia so he cannot use pin system. If a pins system can be used, it is a superior suspension system)

• On left (tan) is the Alps® suspension sleeve. It goes over socket and Easy Liner®

• Both made from silicone. Together they create suction which keep socket prosthetic on. For activities beyond chillin’ and walking, waist belt and V-strap (see below) are needed.

F1, Liner-Sleeve

 

 

Custom Orthopedic Knee Brace (photo: G1, G2, G3)

 

• This brace is made for either copolymer plastic or carbon fiber. It goes over the outside of the prosthetic and around thigh. It’s shape spoons the socket’s coke bottle shape to prevent slippage and twisting of brace on socket.

• It also has stainless steel, limited movement hinges. Only 90° of movement is allowed, preventing hyper-extension of the knee.

• The thigh straps go over top of thigh and are Swiss-style clasps with Velcro.

• Calf straps are customized with old-skool pre-ratchet snowboard bindings. You can find these at local snowboard shop, pawnshop, or flea market. Newer ratchet straps may work, but Lucas has never tried them.

G1, Brace Buckles

G2, Brace Thigh Straps

G3, Brace Leg Coke Bottle

 

 

V-Strap (photo: H1, H2)

 

• V-shape helps to avoid putting pressure on kneecap while riding. All seams are a heave-duty box stitch to keep V-strap from coming apart during high activity.

• To keep V-strap attached and in the proper place, a Velcro strap goes around calf portion of orthopedic knee brace between the old-skool buckles.

• A buckle connects the V-strap to waist belt.

H1, V-Strap Solo

H2, V-Strap Over Knee

 

 

Waist Belt (photo: I1, I2)

 

• It is fitted to ride on and slightly above hips. The buckle holes in the top of the V-strap help adjust the height. Lucas uses a dog collar buckle to attach to the V-strap because conventional buckles not strong enough. A neoprene flap over the buckle protects snow pants from getting a hole due to wear.

• Elastic strap between waist belt and orthopedic brace V-strap allow for movement while box stitching and rivets are added for durability. A security strap made from webbing keeps elastic strap from bottoming out during aggressive shredding and possibly tearing.

I1, Waist Belt and Buckle Protector

I2, Waist Belt and Buckle Protector

 

 

Full Assembly (photo: J1)

 

In total, this prosthetic system is very durable and has a number of safety features built in for protecting the limb and the rider from injury. Please note: this system is unique to Lucas’s type of amputation and many riders are in a system more like what Dan Cav is riding on.

J1, System Overview