Runners with mid‐portion Achilles tendinopathy have greater triceps surae intracortical inhibition than healthy controls

Background: There is disagreement in the literature regarding whether the excessive excursion or velocity of rearfoot eversion is related to the development of 2 common running injuries: Achilles tendinopathy (AT) and medial tibial stress syndrome (MTSS). An alternative hypothesis suggests that the duration of rearfoot eversion may be an important factor. However, the duration of eversion has received relatively little attention in the biomechanics literature. Hypothesis: Runners with AT or MTSS will demonstrate a longer duration of eversion but not greater excursion or velocity of eversion compared with healthy controls. Study Design: Controlled laboratory study. Methods: Forty-two runners participated in this study (13 with AT, 8 with MTSS, and 21 matched controls). Participants were evaluated for lower extremity alignment and flexibility, after which a 3-dimensional kinematic and kinetic running gait analysis was performed. Differences between the 2 injuries and between injured and control participants were evaluated for flexibility and alignment, rearfoot kinematics, and 3 ground-reaction force metrics. Binary logistic regression was used to evaluate which variables best predicted membership in the injured group. Results: Injured participants, compared with controls, demonstrated higher standing tibia varus angles (8.67° ± 1.79° vs 6.76° ± 1.75°, respectively; P = .002), reduced static dorsiflexion range of motion (6.14° ± 5.04° vs 11.19° ± 5.10°, respectively; P = .002), more rearfoot eversion at heel-off (–6.47° ± 5.58° vs 1.07° ± 2.26°, respectively; P < .001), and a longer duration of eversion (86.02% ± 15.65% stance vs 59.12% ± 16.50% stance, respectively; P < .001). There were no differences in the excursion or velocity of eversion. The logistic regression (χ2 = 20.84, P < .001) revealed that every 1% increase in the duration of eversion during the stance phase increased the odds of being in the injured group by 1.08 (95% CI, 1.023-1.141; P = .006). Conclusion: Compared with healthy controls, runners currently symptomatic with AT or MTSS have a longer duration of eversion but not greater excursion or velocity of eversion. Clinical Relevance: Static measures of the tibia varus angle and dorsiflexion range of motion, along with dynamic measures of the duration of eversion, may be useful for identifying runners at risk of sustaining AT or MTSS.

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Flexor hallucis longus hypertrophy secondary to Achilles tendon tendinopathy: an MRI-based case–control study

European Journal of Orthopaedic Surgery & Traumatology ◽

10.1007/s00590-021-02891-8 ◽

2021 ◽

Author(s):

Stephan H. Wirth ◽

Octavian Andronic ◽

Fabian Aregger ◽

Anna Jungwirth-Weinberger ◽

Thorsten Jentzsch ◽

...

Keyword(s):

Achilles Tendon ◽

Achilles Tendinopathy ◽

Diameter Ratio ◽

Triceps Surae ◽

Control Group ◽

Flexor Hallucis Longus ◽

Study Group ◽

Compensatory Mechanism ◽

Indirect Sign ◽

Mri Scans

Abstract Purpose The purpose of this study was to outline an indirect sign of advanced Achilles tendinopathy on magnetic resonance imaging (MRI), based on the hypothesis that these patients would present with secondary hypertrophy of the flexor hallucis longus muscle (FHL). Methods MRI scans of Achilles tendon were analyzed retrospectively in two cohorts. The study group consisted of consecutive patients presenting with clinical signs of Achilles tendinopathy and no previous surgeries, while the control group were patients that had an MRI due to other reasons and no signs of tendinopathy. Two parameters from two muscle bellies were measured and compared on axial MRI scans 4–5 cm above the ankle joint line at the level of greatest thickness: area and diameter of the triceps surae (TS) and of the FHL muscle. Ratios (FHL/TS) were calculated for area (Ar) and diameter (Dm) measurements. Interobserver agreement was analyzed. A receiver operating characteristic (ROC) curve was created for both ratios to assess potential cutoff points to differentiate between the groups. Results A total of 60 patients for each study group were included. Both ratios Ar(FHL/TS) and Dm(FHL/TS) showed significant higher values in the tendinopathy group (p < 0.001). There were strong to very strong intraclass correlation coefficients (ICC = 0.75–0.93). A diameter ratio Dm (FHL/TS) of 2.0 or higher had a sensitivity of 49% and specificity of 90% for concomitant Achilles tendinopathy. Conclusion In our patient cohort, FHL hypertrophy was observed in patients with Achilles tendinopathy as a possible compensatory mechanism. Measuring a diameter ratio Dm(FHL/TS) of 2.0 or higher on an axial MRI, may be indicative as an indirect sign of functional deterioration of the Achilles tendon.

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Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain

Journal of Applied Physiology ◽

10.1152/japplphysiol.00113.2014 ◽

2014 ◽

Vol 117 (2) ◽

pp. 105-111 ◽

Cited By ~ 9

Author(s):

Tahir Masood ◽

Kari Kalliokoski ◽

S. Peter Magnusson ◽

Jens Bojsen-Møller ◽

Taija Finni

Keyword(s):

Achilles Tendon ◽

Glucose Uptake ◽

Plantar Flexion ◽

Achilles Tendinopathy ◽

Triceps Surae ◽

Medial Gastrocnemius ◽

Flexor Hallucis Longus ◽

Myoelectric Activity ◽

Plantar Flexors ◽

Lateral Gastrocnemius

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity and Achilles tendon GU. A longitudinal study design with control ( n = 10) and patient ( n = 10) groups was used. Surface electromyography (SEMG) from four ankle plantar flexors and GU from the same muscles and the Achilles tendon were measured during submaximal intermittent isometric plantar flexion task. The results indicated that the symptomatic leg was weaker ( P < 0.05) than the asymptomatic leg at baseline, but improved ( P < 0.001) with eccentric rehabilitation. Additionally, the rehabilitation resulted in greater GU in both soleus ( P < 0.01) and lateral gastrocnemius ( P < 0.001) in the symptomatic leg, while the asymptomatic leg displayed higher uptake for medial gastrocnemius and flexor hallucis longus ( P < 0.05). While both patient legs had higher tendon GU than the controls ( P < 0.05), there was no rehabilitation effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative activity in the symptomatic leg compared with both the asymptomatic and control legs ( P < 0.05), probably reflecting an effort to compensate for the decreased force potential. The rehabilitation resulted in greater SEMG activity in the lateral gastrocnemius ( P < 0.01) of the symptomatic leg with no other within- or between-group differences. Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle.

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Cortical Excitability and Connectivity in Patients With Brain Tumors

Frontiers in Neurology ◽

10.3389/fneur.2021.673836 ◽

2021 ◽

Vol 12 ◽

Author(s):

Vincenzo Rizzo ◽

Carmen Terranova ◽

Giovanni Raffa ◽

Salvatore Massimiliano Cardali ◽

Filippo Flavio Angileri ◽

...

Keyword(s):

Brain Tumors ◽

Cortical Excitability ◽

Motor Impairment ◽

Silent Period ◽

Intracortical Inhibition ◽

Subcortical White Matter ◽

Short Latency ◽

Precentral Gyrus ◽

Healthy Controls ◽

Afferent Inhibition

Background: Brain tumors can cause different changes in excitation and inhibition at the neuronal network level. These changes can be generated from mechanical and cellular alterations, often manifesting clinically as seizures.Objective/Hypothesis: The effects of brain tumors on cortical excitability (CE) have not yet been well-evaluated. The aim of the current study was to further investigate cortical–cortical and cortical–spinal excitability in patients with brain tumors using a more extensive transcranial magnetic stimulation protocol.Methods: We evaluated CE on 12 consecutive patients with lesions within or close to the precentral gyrus, as well as in the subcortical white matter motor pathways. We assessed resting and active motor threshold, short-latency intracortical inhibition (SICI), intracortical facilitation (ICF), short-latency afferent inhibition (SAI), long-latency afferent inhibition, cortical silent period, and interhemispheric inhibition.Results: CE was reduced in patients with brain tumors than in healthy controls. In addition, SICI, ICF, and SAI were lower in the affected hemisphere compared to the unaffected and healthy controls.Conclusions: CE is abnormal in hemispheres affected by brain tumors. Further studies are needed to determine if CE is related with motor impairment.

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Hyperexcitability and impaired intracortical inhibition in patients with fragile-X syndrome

Translational Psychiatry ◽

10.1038/s41398-019-0650-z ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Florence Morin-Parent ◽

Camille Champigny ◽

Angelina Lacroix ◽

François Corbin ◽

Jean-François Lepage

Keyword(s):

Fragile X Syndrome ◽

Fragile X ◽

Short Interval ◽

Silent Period ◽

Intracortical Inhibition ◽

Primary Objective ◽

Healthy Controls ◽

Intracortical Facilitation ◽

Cortical Hyperexcitability ◽

Resting Motor Threshold

AbstractFragile-X syndrome (FXS) is characterized by neurological and psychiatric problems symptomatic of cortical hyperexcitability. Recent animal studies identified deficient γ-aminobutyricacid (GABA) inhibition as a key mechanism for hyperexcitability in FXS, but the GABA system remains largely unexplored in humans with the disorder. The primary objective of this study was to assess GABA-mediated inhibition and its relationship with hyperexcitability in patients with FXS. Transcranial magnetic stimulation (TMS) was used to assess cortical and corticospinal inhibitory and excitatory mechanisms in 18 patients with a molecular diagnosis of FXS and 18 healthy controls. GABA-mediated inhibition was measured with short-interval intracortical inhibition (GABAA), long-interval intracortical inhibition (GABAB), and the corticospinal silent period (GABAA+B). Net intracortical facilitation involving glutamate was assessed with intracortical facilitation, and corticospinal excitability was measured with the resting motor threshold. Results showed that FXS patients had significantly reduced short-interval intracortical inhibition, increased long-interval intracortical inhibition, and increased intracortical facilitation compared to healthy controls. In the FXS group, reduced short-interval intracortical inhibition was associated with heightened intracortical facilitation. Taken together, these results suggest that reduced GABAA inhibition is a plausible mechanism underlying cortical hyperexcitability in patients with FXS. These findings closely match those observed in animal models, supporting the translational validity of these markers for clinical research.

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