Transferability of strength gains from limited to full range of motion.
OBJECTIVE
This study was aimed at exploring the transferability of short range of motion (RoM) isokinetic conditioning on quadriceps performance inside and outside the trained range.


METHODS
Fifty-five women were randomly assigned to one of four groups: G1 (N = 14) and G2 (N = 14) trained concentrically at 30 and 90degrees x s(-1), respectively, whereas G3 (N = 13) and G4 (N = 14) trained similarly but using the eccentric mode. All four groups trained within 30-60degrees of knee flexion. The training paradigm consisted of 4 sets of 10 maximal repetitions, 3x wk(-1) for a total period of 6 wk. Before the training period and 2 d after its termination, the isokinetic work output (Wisk) was assessed within three angular RoM: 85-60degrees (R1), 60-30degrees (R2), and 30-5degrees (R3). Isometric peak extension moment (PM) and rate of force development (RFD) were evaluated at 10degrees, 45degrees and 80degrees.


RESULTS
Significant increases were observed in the isometric output (at all three angles), Wisk (in R1 and R2), and the RFD (45degrees). The PM increased significantly more in G3 and G4 compared with G1 and G2, evidencing specificity of contraction mode.


CONCLUSIONS
These findings point out to the potential benefits of short RoM conditioning, particularly in those cases where, during specific phases of rehabilitation, a wider RoM may be contraindicative.
Laboratory of Biomechanics, Zinman College of Physical Education and Sport Sciences, Wingate Institute, Netanya, Israel.
Yaron
Y
Barak
Moshe
M
Ayalon
Zeevi
Z
Dvir
D000328:Adult; D015444:Exercise; D005260:Female; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular