The Lower Lumbar Spine Moment and the Axial Rotational Motion of a Body During One-Handed and Double-Handed Backhand Stroke in Tennis

Abstract

To analyze the load on the lumbar spine and the motion pattern of a body during a backhand stroke when playing tennis, kinematic and kinetic data of eleven amateur tennis players were collected. Each subject performed one-handed and double-handed strokes at low, medium, and high racket speeds. The three-dimensional motion of the strokes was optically measured by tracking markers attached to their body segments. Floor reaction forces were measured for the right and left feet separately. Using the body motion and the floor reaction force data, the lower lumbar spine moment was calculated based on a segment-link model. Peak and plateau values of the joint moment before and after ball impact were analyzed statistically using a factorial ANOVA (stroke, racket speed). Similarly, the axial rotation angle of the pelvis against the feet and that of the shoulder against the pelvis were analyzed. In all the moments except the lateral bending moment before ball impact and all the rotation angles, there were significant main effects of racket speed. The one-handed strokes showed significantly smaller extension moment before ball impact as well as smaller lateral bending and axial rotation moments after ball impact than the double-handed strokes. The one-handed strokes also showed a significantly smaller axial rotation angle of the shoulder against the pelvis and that of the pelvis against the feet. These results indicate that during one-handed strokes the shoulder and elbow joints share the rotational motion necessary for backhand strokes and consequently reduce the maximal moments imposed on the spinal joints.

Kinematics - kinetics - low back

References

• 1 de Leva P. Adjustment to Zatsiorsky-Seluyanov's segment inertia parameters.  J Biomechanics. 1996;  29 1223-1230
• 2 Iino Y, Kojima T. Torque acting on the pelvis about its superior-inferior axis through the hip joints during a tennis forehand stroke.  J Human Mov Stud. 2001;  40 269-290
• 3 Kelsey J L, Githens P B, White A A, Holford T R, Walter S D, O'Connor T, Ostfeld A M, Weil U, Southwick W O, Calogero J A. An epidemiologic study of lifting and twisting on the job and risk for acute prolapsed lumbar intervertebral disk.  J Orthop Res. 1984;  2 61-66
• 4 Knudson D, Blackwell J. Trunk muscle activation in open stance and square stance tennis forehands.  Int J Sports Med. 2000;  21 321-324
• 5 Marks M J, Haas S S, Wiesel S W. Low back pain in the competitive tennis players.  Clin Sports Med. 1988;  7 277-287
• 6 Skotte J H. Estimation of low back loading on nurses during patient handling tasks: the importance of bedside reaction force measurement.  J Biomechanics. 2001;  34 273-276
• 7 Sward L, Svensson M, Zetterberg C. Isometric muscle strength and quantitative electromyography of back muscles in wrestlers and tennis players.  Am J Sports Med. 1990;  18 382-386