PMID- 28388231
OWN - NLM
STAT- MEDLINE
DCOM- 20180117
LR  - 20220408
IS  - 1938-162X (Electronic)
IS  - 1062-6050 (Print)
IS  - 1062-6050 (Linking)
VI  - 52
IP  - 5
DP  - 2017 May
TI  - Quadriceps Function and Hamstrings Co-Activation After Anterior Cruciate Ligament 
      Reconstruction.
PG  - 422-428
LID - 10.4085/1062-6050-52.3.05 [doi]
AB  - CONTEXT:   Individuals with anterior cruciate ligament reconstruction (ACLR) have 
      quadriceps dysfunction that contributes to physical disability and posttraumatic 
      knee osteoarthritis. Quadriceps function in the ACLR limb is commonly evaluated 
      relative to the contralateral uninjured limb. Bilateral quadriceps dysfunction is 
      common in individuals with ACLR, potentially biasing these evaluations. 
      OBJECTIVE:   To compare quadriceps function between individuals with ACLR and 
      uninjured control participants. DESIGN:   Cross-sectional study. SETTING:   
      Research laboratory. PATIENTS OR OTHER PARTICIPANTS:   Twenty individuals with 
      unilateral ACLR (age = 21.1 +/- 1.7 years, mass = 68.3 +/- 14.9 kg, time since ACLR = 
      50.7 +/- 21.3 months; females = 14; Tegner Score = 7.1 +/- 0.3; 16 patellar tendon 
      autografts, 3 hamstrings autografts, 1 allograft) matched to 20 control 
      participants (age = 21.2 +/- 1.2 years, mass = 67.9 +/- 11.3 kg; females = 14; Tegner 
      Score = 7.1 +/- 0.4) on age, sex, body mass index, and Tegner Activity Scale. MAIN 
      OUTCOME MEASURE(S):   Maximal voluntary isometric knee extension was performed on 
      an isokinetic dynamometer. Peak torque (PT), rate of torque development (RTD), 
      electromyographic (EMG) amplitude, central activation ratio (CAR), and hamstrings 
      EMG amplitude were assessed during maximal voluntary isometric knee extension and 
      compared between groups using independent-samples t tests. Relationships between 
      hamstrings co-activation and quadriceps function were assessed using Pearson 
      correlations. RESULTS:   Participants with anterior cruciate ligament 
      reconstruction displayed lesser quadriceps PT (1.86 +/- 0.74 versus 2.56 +/- 0.37 
      Nm/kg, P = .001), RTD (39.4 +/- 18.7 versus 52.9 +/- 16.4 Nm/s/kg, P = .03), EMG 
      amplitude (0.25 +/- 0.12 versus 0.37 +/- 0.26 mV, P = .04), and CAR (83.3% +/- 11.1% 
      versus 93.7% +/- 3.2%, P = .002) and greater hamstrings co-activation (27.2% +/- 
      12.8% versus 14.3% +/- 3.7%, P < .001) compared with control participants. 
      Correlations were found between hamstrings co-activation and PT (r = -0.39, P = 
      .007), RTD (r = -0.30, P = .03), and EMG amplitude (r = -0.30, P = .03). 
      CONCLUSIONS:   Individuals with ACLR possessed deficits in PT, RTD, and CAR 
      compared with control participants. Peak torque is the net result of all agonist 
      and antagonist activity, and lesser PT in individuals with ACLR is partially 
      attributable to greater hamstrings co-activation.
FAU - Pamukoff, Derek N
AU  - Pamukoff DN
AD  - California State University, Fullerton.
FAU - Pietrosimone, Brian G
AU  - Pietrosimone BG
AD  - University of North Carolina at Chapel Hill.
FAU - Ryan, Eric D
AU  - Ryan ED
AD  - University of North Carolina at Chapel Hill.
FAU - Lee, Dustin R
AU  - Lee DR
AD  - University of North Carolina at Chapel Hill.
FAU - Blackburn, J Troy
AU  - Blackburn JT
AD  - University of North Carolina at Chapel Hill.
LA  - eng
PT  - Journal Article
DEP - 20170418
PL  - United States
TA  - J Athl Train
JT  - Journal of athletic training
JID - 9301647
SB  - IM
MH  - Adult
MH  - *Anterior Cruciate Ligament Injuries/complications/surgery
MH  - *Anterior Cruciate Ligament Reconstruction/adverse effects/rehabilitation
MH  - Cross-Sectional Studies
MH  - Disability Evaluation
MH  - Female
MH  - Humans
MH  - Knee Joint/*physiopathology
MH  - Male
MH  - Osteoarthritis, Knee/etiology/physiopathology/*prevention & control
MH  - Quadriceps Muscle/*physiopathology
MH  - Range of Motion, Articular
PMC - PMC5455245
OTO - NOTNLM
OT  - arthrogenic muscle inhibition
OT  - electromyography
OT  - muscles
OT  - strength
EDAT- 2017/04/08 06:00
MHDA- 2018/01/18 06:00
PMCR- 2018/05/01
CRDT- 2017/04/08 06:00
PHST- 2017/04/08 06:00 [pubmed]
PHST- 2018/01/18 06:00 [medline]
PHST- 2017/04/08 06:00 [entrez]
PHST- 2018/05/01 00:00 [pmc-release]
AID - JAT0101-16R1 [pii]
AID - 10.4085/1062-6050-52.3.05 [doi]
PST - ppublish
SO  - J Athl Train. 2017 May;52(5):422-428. doi: 10.4085/1062-6050-52.3.05. Epub 2017 
      Apr 18.