Efficacy of inertial training in elbow joint muscles: influence of different movement velocities

The aim of this study was to evaluate the influence of inertial training performed with different movement velocities on elbow flexor and extensor strength and power.

Thirty-eight male physical education students were divided into training and control groups. The two training groups performed inertial training three times per week for five weeks using the Inertial Training Measurement System. Elbow joint flexors and extensors were trained using different maximal movement velocities: 7.50 rad·s(-1) in the faster (TF) group and 5.76 rad·s(-1) in the slower (TS) group. Before and after training, we evaluated maximum force and power of elbow flexors and extensors muscles under training conditions, maximum torque and power of elbow flexors and extensors muscles under isokinetic conditions and maximal power output achieved during upper body Ergometer Test.

Training induced significant increases in elbow flexor force (28.4% in TF and 13.7% in TS) and power (37.7% in TF and 12.4% in TS) measured under training conditions. However, changes in the elbow flexors in the TF group were greater than in the TS group. Elbow extensor force and power measured under inertial conditions increased significantly only in the TF group; 12.5% and 21.1%, respectively. Moreover, the EMG amplitude of the biceps brachii and triceps brachii and upper limb muscle mass increased in both training groups. Measurements made under isokinetic conditions indicated that torque and power improved only in the elbow flexors, no changes in maximal power output were observed during the upper limb Ergometer Test.

The short-term inertial training resulted in significant elbow muscles strength and power improvements. ITMS training induced also the increase of upper limbs muscle mass and the increase of EMG activity of muscles during flexion and extension of elbow. Moreover, greater movement velocities seem to be a benefit for strength and power enhancement. However, further studies are needed to confirm this suggestion.