Speed, not magnitude, of knee extensor torque production is associated with self-reported knee function early after anterior cruciate ligament reconstruction

Hsieh, Chao-Jung; Indelicato, Peter A.; Moser, Michael W.; Vandenborne, Krista; Chmielewski, Terese L.

doi:10.1007/s00167-014-3168-1

Cited by 48 publications

(59 citation statements)

References 48 publications

(61 reference statements)

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“…This decrease in isokinetic RTD supports previous theories of researchers 15,51 who suggested that a lower RTD may be determined by a lack of afferent feedback from the reconstructed ACL, ultimately inhibiting the recruitment of high-threshold motor units. A lower RTD may also indicate a longer period is needed for higher-threshold motor units to activate.…”

Section: Isokinetic Interlimb Asymmetriessupporting

confidence: 86%

“…20,30 The TTP was calculated (TTP ¼ time of peak torque -time of onset of torque) for both isometric and isokinetic data. 15 A representation of how the isometric and isokinetic data were analyzed is shown in Figures 1 and 2, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…For descriptive purposes, the percentage differences/symmetry values ([involved limb / uninvolved limb] 3 100) for the dependent measures were also calculated. 7,15 To determine if interlimb asymmetries were clinically meaningful, we conducted standardized effect sizes (ESs) and 95% confidence intervals (CIs) and interpreted ESs as weak (,0.5), moderate (0.5-0.79), or strong (.0.8). 31 The a level was set a priori at P .05.…”

Section: Discussionmentioning

confidence: 99%

“…Whereas not used as often, the time needed to reach peak torque (TTP) and the rate of torque development (RTD) can help to quantify changes in muscle that lead to quadriceps weakness. 15 Deficits in the TTP and RTD can be regulated by several underlying factors, including a decline in neural activation, 16,17 a shift in fiber types after injury, 18 and changes in the contractile elements of muscle fibers or the tendon structure.…”

mentioning

confidence: 99%

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Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Johnson¹,

Palmieri-Smith

Lepley

2018

Journal of Athletic Training

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Context: To quantify quadriceps weakness after anterior cruciate ligament reconstruction (ACLR), researchers have often analyzed only peak torque. However, analyzing other characteristics of the waveform, such as the rate of torque development (RTD), time to peak torque (TTP), and central activation ratio (CAR), can lend insight into the underlying neuromuscular factors that regulate torque development.Objective: To determine if interlimb neuromuscular asymmetry was present in patients with ACLR at the time of clearance to return to activity.Design: Cross-sectional study. Conclusions: Interlimb asymmetries at return to activity after ACLR appeared to be regulated by several underlying neuromuscular factors. We theorize that interlimb asymmetries in isometric and isokinetic quadriceps strength were associated with changes in muscle architecture. Reduced CAR, TTP, and RTD were also present, indicating a loss of motor-unit recruitment or decrease in firing rate.

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Section: Isokinetic Interlimb Asymmetriessupporting

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Johnson¹,

Palmieri-Smith

Lepley

2018

Journal of Athletic Training

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“…19 The ability to produce quick or explosive movements is often more important than muscle strength 19 in sporting activities, and speed rather than magnitude is associated with self-reported physical function in individuals with ACLR. 20 Therefore, the rate of torque development (RTD) is an important indicator of quadriceps function in individuals with ACLR 21 and is associated with greater ground reaction forces and loading rates during walking gait.…”

Section: à6mentioning

confidence: 99%

Quadriceps Function and Hamstrings Co-Activation After Anterior Cruciate Ligament Reconstruction

Pamukoff

Pietrosimone

Ryan

et al. 2017

Journal of Athletic Training

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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 ¼ 21.1 6 1.7 years, mass ¼ 68.3 6 14.9 kg, time since ACLR ¼ 50.7 6 21.3 months; females ¼ 14; Tegner Score ¼ 7.1 6 0.3; 16 patellar tendon autografts, 3 hamstrings autografts, 1 allograft) matched to 20 control participants (age ¼ 21.2 6 1.2 years, mass ¼ 67.9 6 11.3 kg; females ¼ 14; Tegner Score ¼ 7.1 6 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 6 0.74 versus 2.56 6 0.37 Nm/kg, P ¼ .001), RTD (39.4 6 18.7 versus 52.9 6 16.4 Nm/s/kg, P ¼ .03), EMG amplitude (0.25 6 0.12 versus 0.37 6 0.26 mV, P ¼ .04), and CAR (83.3% 6 11.1% versus 93.7% 6 3.2%, P ¼ .002) and greater hamstrings co-activation (27.2% 6 12.8% versus 14.3% 6 3.7%, P , .001) compared with control participants. Correlations were found between hamstrings co-activation and PT (r ¼ À0.39, P ¼ .007), RTD (r ¼ À0.30, P ¼ .03), and EMG amplitude (r ¼ À0.30, P ¼ .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.

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Quadriceps function relates to muscle size following ACL reconstruction

Kuenze

Blemker

Hart

2016

Journal Orthopaedic Research

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ABSTRACT:It remains unclear what role reduced volume and cross-section area (CSA) of individual quadriceps muscles may play in persistent quadriceps weakness and more global dysfunction following ACL reconstruction (ACLR). The purpose of this investigation was to establish the relationship between cross-sectional area of the quadriceps muscle group and measures of knee related and quadriceps function following ACLR. Thirty participants with a history of primary, unilateral ACLR experiencing persistent quadriceps activation failure participated in this cohort study. Clinical factors including International Knee Documentation Committee (IKDC) score, normalized knee extension MVIC torque (Nm/kg) and quadriceps central activation ratio (CAR, %) were assessed in addition to CSA. Quadriceps CSA was measured via magnetic resonance imaging (MRI; Siemens Avanto 1.5T). Quadriceps CSA (cm 2 ) and quadriceps volume (cm 3 ) as well as individual muscle estimates were identified within a 10 cm mid-thigh capture area. Pearson's product-moment correlation coefficients (r) established relationships between CSA and all other variables. Stepwise linear regression established which CSA factors were able to successfully predict clinical factors. Knee extension MVIC torque was strongly correlated with Vastus Intermedius (VI; r ¼ 0.857, p < 0.001) CSA as well as partial VI (r ¼ 0.849, p < 0.001) and quadriceps (r ¼ 0.830, p < 0.001) volume. Partial VI (r ¼ 0.365, p ¼ 0.047) volume was weakly correlated with IKDC score. Knee extension MVIC torque was strongly predicted using VI CSA alone (R 2 ¼ 0.725) or in combination with Vastus Medialis CSA (VM; R 2 ¼ 0.756). Statement of Clinical Significance: Atrophy of the VI and VM muscles negatively impacts knee extension strength following ACLR. ß

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Speed, not magnitude, of knee extensor torque production is associated with self-reported knee function early after anterior cruciate ligament reconstruction

Abstract: III.

Cited by 48 publications

References 48 publications

Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Quadriceps Function and Hamstrings Co-Activation After Anterior Cruciate Ligament Reconstruction

Quadriceps function relates to muscle size following ACL reconstruction

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