Tuff Stuff Fitness Bio-Arc Line: Optimal Mechanics for Muscle Activation

Innovation  Intuition  Inspiration…key characteristics that describe the new Bio-Arc line of equipment designed and developed by TuffStuff Fitness International (TFI) which incorporates the patented Bio-Arc Technology which is distinctive to selectorized machines within the fitness market in that the user’s entire body moves along with the machine as each exercise is performed.

When developing Bio-Arc, TFI collaborated with an Independent Research & Consulting Company during R&D. The goal was to go through the development phase and put each machine through a test protocol using Electromyographical (EMG) testing to examine and compare the recruitment patterns of the primary movers, accessory and antagonistic muscle groups during the full range of motion on the Bio-Arc machines.

The researchers that collaborated with TFI’s R&D team of engineers identified 3 of the 9 machines and deemed them of exceptional bio-mechanics and positioning of the users body, and felt they did not need to be modified biomechanically. The independent research team tested the remaining 6 units in order to optimize final design specifications.

The EMG testing was performed during a series of design modifications to determine the optimal mechanics for muscle activation.  Subjects (three male and one female) were selected for EMG and goniometer testing, ranging from the lower and upper height range (5’-6’2”) of traditional lines of equipment. For EMG testing, subject selection was limited to individuals with lower than average body fat to permit accurate measurement of muscle activity. Prior to measurements on each machine, subjects practiced each movement and determined a self-described moderate-heavy load on each exercise.

Per test protocol, surface electrodes were placed on the skin overlying the select muscle groups for each exercise. EMG activity was recorded during eight to ten repetitions and measured to include both the activity during the concentric and eccentric phases of contraction, as well as, the recovery phase of each repetition. This allowed for analysis of the muscle activity during the full range of motion and muscle engagement throughout each set on each machine. Modifications on the machines dimensions were made in equal increments that were marked on each telescopic beam or tube, to allow for adjustment through the range of length, height or angular changes. Data was recorded for each of the test subjects in each individual setting. Once completed, data was analyzed to determine the optimal dimensions of the unit selected for final production.

Goniometer testing was performed on all nine of the pieces within the Bio-Arc equipment line for proper design of head pads and/or foot support. Measurements of head-neck-torso and hip-torso were performed to assure appropriate neck and lower back flexion or extension to avoid hyperextension, limiting neck and lumbar stress.

As a result of key findings and modifications during the testing phase and that were ultimately made in production, Bio-Arc Technology safely places users of all physical abilities in the optimal position to perform each individual exercise, with minimal adjustments necessary, for maximum activation of the target muscle(s), while minimizing joint stress throughout the entire range of motion.