TY - JOUR
T1 - Hop tests can result in higher limb symmetry index values than isokinetic strength and leg press tests in patients following ACL reconstruction
AU - Nagai, Takashi
AU - Schilaty, Nathan D.
AU - Laskowski, Edward R.
AU - Hewett, Timothy E.
N1 - Funding Information:
The authors would like to acknowledge our subjects for their wiliness to participate in the study and the funding agency: the National Institute of Health (NIH) and grants: R01-AR056259 and R01-AR055563. We thank Mr. Eric M. Crowley from the Mayo Clinic Sports Medicine Center for his assistance in subject recruitment and scheduling. We also thank Mr. Daniel V. Gaz, Mr. Thomas M. Rieck, and staff members from the Mayo Clinic Healthy Living Program for their generosity to let us use their leg press machine.
Publisher Copyright:
© 2019, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).
PY - 2020/3/1
Y1 - 2020/3/1
N2 - Purpose: Quadriceps weakness is a common clinical sign following anterior cruciate ligament injury and reconstruction surgery (ACLR). The aim of this study was to compare strength deficits and the limb symmetry index (LSI) from three different types of functional tests: isokinetic dynamometry, hop test, and leg press. Methods: A total of 26 subjects with ACLR (average 8.3 months post-operation) participated in the study. The peak knee extension torque was tested with isokinetic dynamometry at 60/180/300 °/s (ISO60/180/300). Hop distance was tested during single hop (SH) and triple hop (TH). Unilateral peak leg power (POWER) was tested during a bilateral leg press test. LSI was calculated as the ratio of the involved limb over the uninvolved limb values. Pearson correlation coefficients and paired t-tests were used to establish relationships among ISO60/180/300, SH/TH, and POWER values and compare these values between the limbs, respectively. Within-subject one-way analysis of variance (ANOVA) with post hoc analyses was used to compare LSI values among different tests. Results: ISO60/180/300 values were significantly positively correlated with SH/TH and POWER (P < 0.05), while SH/TH and POWER values were not significantly correlated. Significant limb differences were found in all tests (P = 0.001–0.008). ANOVA revealed significant LSI differences among different tests. Specifically, post hoc analyses revealed that LSI during SH was significantly higher than LSI during ISO60. Similarly, LSI during TH was significantly higher than LSIs from ISO60, ISO180, and POWER tests. Conclusions: Peak knee extension torque values were positively associated with hop distance and leg power during the leg press test. However, LSI values should be interpreted with caution as hop tests provided significantly higher LSI values than isokinetic testing. Both isokinetic dynamometry and unilateral leg press machine could be used to isolate and strengthen the quadriceps in the involved limb. The current “gold standard” isokinetic testing at slow speed (ISO60) provided the lowest LSI value among all functional tests; therefore, the current study supported a continued use of isokinetic testing when examining individual’s readiness and return-to-sport. Level of evidence: III.
AB - Purpose: Quadriceps weakness is a common clinical sign following anterior cruciate ligament injury and reconstruction surgery (ACLR). The aim of this study was to compare strength deficits and the limb symmetry index (LSI) from three different types of functional tests: isokinetic dynamometry, hop test, and leg press. Methods: A total of 26 subjects with ACLR (average 8.3 months post-operation) participated in the study. The peak knee extension torque was tested with isokinetic dynamometry at 60/180/300 °/s (ISO60/180/300). Hop distance was tested during single hop (SH) and triple hop (TH). Unilateral peak leg power (POWER) was tested during a bilateral leg press test. LSI was calculated as the ratio of the involved limb over the uninvolved limb values. Pearson correlation coefficients and paired t-tests were used to establish relationships among ISO60/180/300, SH/TH, and POWER values and compare these values between the limbs, respectively. Within-subject one-way analysis of variance (ANOVA) with post hoc analyses was used to compare LSI values among different tests. Results: ISO60/180/300 values were significantly positively correlated with SH/TH and POWER (P < 0.05), while SH/TH and POWER values were not significantly correlated. Significant limb differences were found in all tests (P = 0.001–0.008). ANOVA revealed significant LSI differences among different tests. Specifically, post hoc analyses revealed that LSI during SH was significantly higher than LSI during ISO60. Similarly, LSI during TH was significantly higher than LSIs from ISO60, ISO180, and POWER tests. Conclusions: Peak knee extension torque values were positively associated with hop distance and leg power during the leg press test. However, LSI values should be interpreted with caution as hop tests provided significantly higher LSI values than isokinetic testing. Both isokinetic dynamometry and unilateral leg press machine could be used to isolate and strengthen the quadriceps in the involved limb. The current “gold standard” isokinetic testing at slow speed (ISO60) provided the lowest LSI value among all functional tests; therefore, the current study supported a continued use of isokinetic testing when examining individual’s readiness and return-to-sport. Level of evidence: III.
KW - ACL reconstruction
KW - Arthrogenic inhibition
KW - Hop tests
KW - Isokinetic
KW - Leg press
KW - Quadriceps weakness
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U2 - 10.1007/s00167-019-05513-3
DO - 10.1007/s00167-019-05513-3
M3 - Article
C2 - 31025059
AN - SCOPUS:85065086756
SN - 0942-2056
VL - 28
SP - 816
EP - 822
JO - Knee Surgery, Sports Traumatology, Arthroscopy
JF - Knee Surgery, Sports Traumatology, Arthroscopy
IS - 3
ER -