Pedal Motion Geometry of Ellipticals Machines

Pedal Motion Geometry plays a major role in the biomechanical performance of an elliptical machine. It influences muscle engagement, user comfort, and exercise effectiveness.

Pedal Motion Geometry

Pedal Motion Geometry is defined by three motion ranges: stride, lift, and pedal tilt.

Horizontal Stride

Horizontal stride defines how far the feet travel forward and backward during each pedal cycle. A longer stride creates a motion that more closely resembles walking or running, with greater hip movement, while a shorter stride provides a more compact stepping motion that is easier to maintain at higher resistance.

Vertical Lift

Vertical lift defines how much the body moves upward during each pedal cycle. A higher lift requires more work against gravity, increasing lower-body muscle involvement and exercise intensity. A lower lift results in a flatter, less demanding motion.

Pedal Tilt

Pedal tilt defines how much the feet rotate throughout each pedal cycle. A moderate tilt encourages natural ankle movement and improves comfort, whereas excessive tilt increases ankle rotation and may reduce comfort during extended workouts.

Mechanical Designs

Elliptical machines are bar-linkage systems. The length, position and motion relationship of the linkages determine the pedal motion geometry.

Four-Bar Linkage and Glide Linkage are the two rudimentary mechanical structures that most designs are based on.

Manufacturers adopt different design variations for different applications, balancing trade-offs among machine size, mechanical complexity, and the desired pedal motion geometry.

Four-Bar Linkage

Four-Bar Linkage is the classic design for elliptical machines. It is characterized by a long machine frame with a large rear-mounted flywheel.

Long Coupler

The long-coupler design is representative of typical commercial elliptical machines. It offers a decent stride and comfortable pedal tilt range.

Long Machine Frame o achieve a sufficient stride length, the crank joint is typically positioned near the rim of the large flywheel. The coupler must also be long enough to keep the pedal tilt within an ergonomic range, typically less than 20°. As a result, the machine requires a long frame.

Horizontal Elliptical The large flywheel is typically positioned near the floor, requiring the coupler to remain nearly parallel to the ground. As a result, the pedal follows a predominantly horizontal elliptical trajectory, characterized by a long stride and relatively small lift.

Short Coupler

Short Machine Frame A shorter coupler reduces the overall machine length, making this design well suited for home-use elliptical machines. The trade-off is a larger pedal tilt range, which may increase stress on the ankles.

Short Crank

Short-crank design is another approach to reducing machine size. The flywheel is also typically downsized in this design, resulting in a reduced pedal motion range and less smooth resistance.

Compromised Design This design is a compromise that primarily targets budget-conscious buyers and users with limited home space.

Glide Linkage

Glide Linkage evolved from the classic Four-Bar Linkage. Instead of mounting the pedal directly to the coupler, a separate pedal bar is introduced and hinged to the coupler. One end of the coupler remains connected to the crank, while the other end moves on a roller that glides along either a rail fixed to the machine frame or a rotating crank joint.

Glide on Fixed Rail

High Lift The Glide on Fixed Rail design offers a higher vertical lift while maintaining a moderate pedal tilt range.

Glide on Crank Joint

Long Stride The Glide on Crank Joint design produces a longer stride while keeping the pedal tilt in a small range.

The Glide Linkage design adds an additional degree of freedom to the four-bar linkage, allowing the pedal motion geometry to be less restricted by the coupler position, giving designers much greater flexibility to optimize stride, lift, pedal tilt, and machine size.

Most front-drive and center-drive types of elliptical machines adopt one of these two Glide Linkage designs.

LB007 Vertical Elliptical 5x11

While most elliptical machines produce a predominantly horizontal pedal trajectory with a long stride and low lift, LB007 produces a predominantly vertical trajectory with a short stride and high lift.

Unlike conventional ellipticals, in which the pedals directly drive the flywheel, LB007 uses a two-stage transmission that decouples the pedal mechanism from the flywheel. This allows the crank wheel to be positioned independently of the flywheel, giving designers much greater freedom to optimize the pedal motion geometry.

Vertical EllipticalThe freedom in crank wheel placement enables LB007's predominantly vertical elliptical pedal motion geometry.

Small Footprint he compact two-stage drivetrain and small flywheel allow LB007 to achieve the desired stride, lift, and pedal tilt while maintaining a small footprint.

LB007's Pedal Motion Geometry was refined through multiple rounds of prototyping, biomechanical analysis, and user inputs.

Summary

Pedal Motion Geometry largely determines the biomechanical performance of an elliptical machine. It is defined by three key parameters: horizontal stride, vertical lift, and pedal tilt.

Different mechanical architectures produce different pedal motion geometries. Four-Bar Linkage and Glide Linkage designs each involve engineering trade-offs among machine size, mechanical complexity, motion smoothness, and exercise characteristics.

The LB007 Vertical Elliptical 5×11™ adopts a two-stage transmission that decouples the pedal mechanism from the flywheel. This architecture provides greater freedom to optimize pedal motion geometry, enabling a compact elliptical machine with a predominantly vertical pedal trajectory.