Motorized Cable Resistance Control for Eccentric Strength Training
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional strength training methods lack the ability to dynamically adjust resistance to accommodate individual muscle tension variations and asymmetric protocols, making it challenging to achieve optimal muscle engagement and tendon strengthening, especially in eccentric loading phases.
Innovation Solution
A digital strength trainer system using a three-phase brushless DC motor controlled by a processor to dynamically adjust torque, allowing for arbitrary applied tension curves and phase changes, mimicking the behavior of a weight stack while providing haptic feedback and adaptive resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional strength training methods are used, then simplicity and ease of operation are maintained, but the ability to dynamically adjust resistance to match individual muscle tension variations is lost
Solution Approach 1:
The patent replaces traditional mechanical weight stacks with an electric motor system that uses electrical control to generate resistance. The motor controller dynamically adjusts torque output based on feedback from encoders and force sensors, enabling adaptive resistance without the mechanical complexity of multiple weight plates and pulleys. This substitution allows programmable resistance curves while maintaining a relatively simple physical structure.
Solution Approach 2:
The system implements dynamic resistance adjustment by continuously modifying motor torque during exercise movements. Encoders track joint angles and movement velocity, while force sensors measure applied load. The controller uses this real-time data to adjust resistance levels dynamically, creating adaptive resistance curves that match individual muscle tension variations throughout the range of motion.
2Adaptability or versatility
If fixed weight stacks are used, then device simplicity is maintained, but the ability to provide asymmetric protocols and phase changes is limited
Solution Approach 1:
The system enables asymmetric protocols by dynamically adjusting resistance differently during concentric and eccentric phases of movement. The controller programs distinct torque profiles for each phase, allowing higher resistance during lowering (eccentric) and lower resistance during lifting (concentric). This dynamic control achieves asymmetric loading without requiring separate weight stacks for each phase.
Solution Approach 2:
The system changes resistance parameters programmatically based on movement phase, velocity, and position. The controller modifies torque output, speed, and acceleration parameters in real-time to create varied resistance curves. This allows implementation of different training protocols (asymmetric, phase-specific, velocity-dependent) by simply changing software parameters rather than physical configuration.
3Reliability
If traditional weight training is performed alone, then convenience and accessibility are improved, but safety and proper form guidance are compromised
Solution Approach 1:
The system incorporates multiple sensors (encoders, force sensors, position sensors) that continuously monitor movement quality, resistance applied, and joint angles. This feedback is processed by the controller to detect improper form, excessive loads, or unsafe movement patterns. The system can then provide real-time alerts, adjust resistance automatically, or stop the exercise to prevent injury, ensuring safety even when used independently.
Solution Approach 2:
The system provides automated safety monitoring and form guidance without requiring a trainer present. The control system independently analyzes sensor data, compares it against safe movement parameters, and takes corrective action when needed. This self-monitoring capability maintains safety while preserving the convenience of independent home workouts.
4Productivity
If high weight strength training is performed, then training effectiveness is improved, but the risk of injury and difficulty in starting/stopping alone increases
Solution Approach 1:
The system enables high-weight training by dynamically controlling motor torque to provide smooth, progressive resistance increases. The controller can ramp up torque gradually during the concentric phase and control the deceleration during eccentric phase, making heavy loads manageable and controllable. This dynamic torque control allows users to safely handle high resistance levels that would be difficult or dangerous with traditional free weights.
Solution Approach 2:
Force sensors and encoders continuously monitor the actual load and movement velocity. The controller uses this feedback to ensure resistance remains within safe limits and to detect signs of struggling or loss of control. If the user exceeds safe force thresholds or shows signs of improper form under high load, the system can automatically reduce resistance or stop the exercise, preventing injury while maintaining training effectiveness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient, safe, and effective strength training by dynamically adjusting resistance to match individual muscle tension and phase requirements, enhancing muscle engagement and tendon strengthening, particularly in eccentric loading phases, and providing a more comfortable and natural workout experience.
Implementation Method 1
a three-phase brushless DC motor controlled by a processor to dynamically adjust torque
Data Source
AI summary
Assisted racking of digital resistance includes detecting a state of a cable. A motor is mechanically coupled to the cable to provide resistance during an exercise by tensioning the cable. It further includes determining completion of the exercise based at least in part on the detected state of the cable. It further includes selectively removing resistance from the cable based at least in part on the determination that the user has completed the exercise.