Lower Leg Cold Immersion Does Not Impair Dynamic Stability in Healthy Women

2005 ◽  
Vol 14 (3) ◽  
pp. 235-247 ◽  
Author(s):  
Susan Miniello ◽  
Geoffrey Dover ◽  
Michael Powers ◽  
Mark Tillman ◽  
Erik Wikstrom
Keyword(s):  
Dynamic Stability ◽  
Outcome Measures ◽  
Tibialis Anterior ◽  
Lower Leg ◽  
Electromyographic Activity ◽  
Peroneus Longus ◽  
Jump Landing ◽  
Healthy Women ◽  
Time To Stabilization ◽  
Cold Immersion

Context:Previous studies have suggested that cryotherapy affects neuromuscu-lar function and therefore might impair dynamic stability. If cryotherapy affects dynamic stability, clinicians might alter their decisions regarding returning athletes to play immediately after treatment.Objective:To assess the effects of lower leg cold immersion on muscle activity and dynamic stability of the lower extremity.Design:Within-subject time-series design with 1 pretest and 2 posttests.Setting:A climate-controlled biomechanics laboratory.Participants:17 healthy women.Interventions:20-minute cold-water immersion.Main Outcome Measures:Preparatory and reactive electromyographic activity of the tibialis anterior and peroneus longus and time to stabilization after a jump landing.Results:Preparatory activity of the tibialis anterior increased after treatment, whereas preparatory and reactive peroneus longus activity decreased. Both returned to baseline after a 5-minute recovery. Time to stabilization did not change.Conclusions:Lower leg cold-immersion therapy does not impair dynamic stability in healthy women during a jump-landing task. Return to participation after a cryotherapy treatment is not contraindicated for healthy athletes.

scholarly journals Ankle Bracing, Fatigue, and Time to Stabilization in Collegiate Volleyball Athletes

2008 ◽  
Vol 43 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Megan Y. Shaw ◽  
Phillip A. Gribble ◽  
Jamie L. Frye
Keyword(s):  
Dynamic Stability ◽  
Repeated Measures ◽  
Force Plate ◽  
Starting Position ◽  
Jump Landing ◽  
Time Interaction ◽  
Ankle Brace ◽  
Time To Stabilization ◽  
Post Hoc ◽  
Anterior Posterior

Abstract Context: Fatigue has been shown to disrupt dynamic stability in healthy volunteers. It is not known if wearing prophylactic ankle supports can improve dynamic stability in fatigued athletes. Objective: To determine the type of ankle brace that may be more effective at providing dynamic stability after a jump-landing task during normal and fatigued conditions. Design: Two separate repeated-measures analyses of variance with 2 within-subjects factors (condition and time) were performed for each dependent variable. Setting: Research laboratory. Patients or Other Participants: Ten healthy female collegiate volleyball athletes participated (age  =  19.5 ± 1.27 years, height  =  179.07 ± 7.6 cm, mass  =  69.86 ± 5.42 kg). Intervention(s): Athletes participated in 3 separate testing sessions, applying a different bracing condition at each session: no brace (NB), Swede-O Universal lace-up ankle brace (AB), and Active Ankle brace (AA). Three trials of a jump-landing task were performed under each condition before and after induced functional fatigue. The jump-landing task consisted of a single-leg landing onto a force plate from a height equivalent to 50% of each participant's maximal jump height and from a starting position 70 cm from the center of the force plate. Main Outcome Measure(s): Time to stabilization in the anterior-posterior (APTTS) and medial-lateral (MLTTS) directions. Results: For APTTS, a condition-by-time interaction existed (F2,18  =  5.55, P  =  .013). For the AA condition, Tukey post hoc testing revealed faster pretest (2.734 ± 0.331 seconds) APTTS than posttest (3.817 ± 0.263 seconds). Post hoc testing also revealed that the AB condition provided faster APTTS (2.492 ± 0.271 seconds) than AA (3.817 ± 0.263 seconds) and NB (3.341 ± 0.339 seconds) conditions during posttesting. No statistically significant findings were associated with MLTTS. Conclusions: Fatigue increased APTTS for the AA condition. Because the AB condition was more effective than the other 2 conditions during the posttesting, the AB appears to be the best option for providing dynamic stability in the anterior-posterior direction during a landing task.

Relationship Between Gluteal Muscle Strength, Corticospinal Excitability, and Jump-Landing Biomechanics in Healthy Women

2013 ◽  
Vol 22 (4) ◽  
pp. 239-247 ◽  
Author(s):  
Adam S. Lepley ◽  
Allison M. Strouse ◽  
Hayley M. Ericksen ◽  
Kate R. Pfile ◽  
Phillip A. Gribble ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Outcome Measures ◽  
Motor Evoked Potentials ◽  
Gluteus Maximus ◽  
Gluteus Medius ◽  
Corticospinal Excitability ◽  
Gluteal Muscle ◽  
Jump Landing ◽  
Healthy Women ◽  
Landing Biomechanics

Context:Components of gluteal neuromuscular function, such as strength and corticospinal excitability, could potentially influence alterations in lower extremity biomechanics during jump landing.Objective:To determine the relationship between gluteal muscle strength, gluteal corticospinal excitability, and jump-landing biomechanics in healthy women.Setting:University laboratory.Design:Descriptive laboratory study.Participants:37 healthy women (21.08 ± 2.15 y, 164.8 ± 5.9 cm, 65.4 ± 12.0 kg).Interventions:Bilateral gluteal strength was assessed through maximal voluntary isometric contractions (MVIC) using an isokinetic dynamometer. Strength was tested in the open chain in prone and side-lying positions for the gluteus maximus and gluteus medius muscles, respectively. Transcranial magnetic stimulation was used to elicit measures of corticospinal excitability. Participants then performed 3 trials of jump landing from a 30-cm box to a distance of 50% of their height, with an immediate rebound to a maximal vertical jump. Each jump-landing trial was video recorded (2-D) and later scored for errors.Main Outcome Measures:MVICs normalized to body mass were used to assess strength in the gluteal muscles of the dominant and nondominant limbs. Corticospinal excitability was assessed by means of active motor threshold (AMT) and motor-evoked potentials (MEP) elicited at 120% of AMT. The Landing Error Scoring System (LESS) was used to evaluate jump-landing biomechanics.Results:A moderate, positive correlation was found between dominant gluteus maximus MEP and LESS scores (r = .562, P = .029). No other significant correlations were observed for MVIC, AMT, or MEP for the gluteus maximus and gluteus medius, regardless of limb.Conclusions:The findings suggest a moderate relationship between dominant gluteus maximus corticospinal excitability and a clinical measure of jump-landing biomechanics. Further research is required to substantiate the findings and expand our understanding of the central nervous system’s role in athletic movement.

The Effect of Jump-Landing Directions on Dynamic Stability

2013 ◽  
Vol 29 (5) ◽  
pp. 634-638 ◽  
Author(s):  
Kathy Liu ◽  
Gary D. Heise
Keyword(s):  
Dynamic Stability ◽  
Reaction Force ◽  
Body Height ◽  
Force Plate ◽  
Forward Direction ◽  
Female Age ◽  
Jump Landing ◽  
Time To Stabilization ◽  
Vertical Jumps ◽  
Anterior Posterior

Dynamic stability is often measured by time to stabilization (TTS), which is calculated from the dwindling fluctuations of ground reaction force (GRF) components over time. Common protocols of dynamic stability research have involved forward or vertical jumps, neglecting different jump-landing directions. Therefore, the purpose of the present investigation was to examine the influence of different jump-landing directions on TTS. Twenty healthy participants (9 male, 11 female; age = 28 ± 4 y; body mass = 73.3 ± 21.5 kg; body height = 173.4 ± 10.5 cm) completed the Multi-Directional Dynamic Stability Protocol hopping tasks from four different directions—forward, lateral, medial, and backward—landing single-legged onto the force plate. TTS was calculated for each component of the GRF (ap = anterior-posterior; ml = medial-lateral; v = vertical) and was based on a sequential averaging technique. All TTS measures showed a statistically significant main effect for jump-landing direction. TTSml showed significantly longer times for landings from the medial and lateral directions (medial: 4.10 ± 0.21 s, lateral: 4.24 ± 0.15 s, forward: 1.48 ± 0.59 s, backward: 1.42 ± 0.37 s), whereas TTSap showed significantly longer times for landings from the forward and backward directions (forward: 4.53 ± 0.17 s, backward: 4.34 0.35 s, medial: 1.18 ± 0.49 s, lateral: 1.11 ± 0.43 s). TTSv showed a significantly shorter time for the forward direction compared with all other landing directions (forward: 2.62 ± 0.31 s, backward: 2.82 ± 0.29 s, medial: 2.91 ± 0.31 s, lateral: 2.86 ± 0.32 s). Based on these results, multiple jump-landing directions should be considered when assessing dynamic stability.

Lower-Extremity Muscle Activity During Aquatic and Land Treadmill Running at the Same Speeds

2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Swing Phase ◽  
Treadmill Running ◽  
Vastus Medialis ◽  
Lower Extremity Muscle

Context:Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.Objectives:The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.Design:Exploratory, quasi-experimental, crossover design.Setting:Athletic training facility.Participants:12 healthy recreational runners (age = 25.8 ± 5 y, height = 178.4 ± 8.2 cm, mass = 71.5 ± 11.5 kg, running experience = 8.2 ± 5.3 y) volunteered for participation.Intervention:All participants performed TM and ATM running at 174.4, 201.2, and 228.0 m/min while surface electromyographic data were collected from the vastus medialis, rectus femoris, gastrocnemius, tibialis anterior, and biceps femoris.Main Outcome Measures:For each muscle, a 2 × 3 repeated-measures ANOVA was used to analyze the main effects and environment–speed interaction (P ≤ .05) of each dependent variable: %MVC, aDUR, and tACT.Results:Compared with TM, ATM elicited significantly reduced %MVC (−44.0%) but increased aDUR (+213.1%) and tACT (+41.9%) in the vastus medialis, increased %MVC (+48.7%) and aDUR (+128.1%) in the rectus femoris during swing phase, reduced %MVC (−26.9%) and tACT (−40.1%) in the gastrocnemius, increased aDUR (+33.1%) and tACT (+35.7%) in the tibialis anterior, and increased aDUR (+41.3%) and tACT (+29.2%) in the biceps femoris. At faster running speeds, there were significant increases in tibialis anterior %MVC (+8.6−15.2%) and tACT (+12.7−17.0%) and rectus femoris %MVC (12.1−26.6%; swing phase).Conclusion:No significant environment–speed interaction effects suggested that observed muscle-activity differences between ATM and TM were due to environmental variation, ie, buoyancy (presumed to decrease %MVC) and drag forces (presumed to increase aDUR and tACT) in the water.

The Correspondence Between Some Motor Points and Acupuncture Loci

1975 ◽  
Vol 03 (04) ◽  
pp. 347-358 ◽  
Author(s):  
Y. King Liu ◽  
Maria Varela ◽  
Robert Oswald
Keyword(s):  
Statistical Analysis ◽  
Tibialis Anterior ◽  
Double Blind Study ◽  
Vastus Medialis ◽  
Abductor Pollicis Brevis ◽  
Double Blind ◽  
Orbicularis Oculi ◽  
Peroneus Longus ◽  
Uv Illumination ◽  
Splenius Capitis

A double blind study was conducted to establish the possible correspondence between some motor points and acupuncture loci. THe protocol calls for the acupuncturist marking the first group of volunteers with invisible ink at the acupuncture loci. Then the motor points in the same volunteer are found by electrodiagnosis. The error is made visible by UV illumination. In the second group, the procedure is reversed. A statistical analysis of the error yields the following classes of correspondences: (a) Excellent: 1st Dorsal Interosseus (hand) = LI-4; Abductor Pollicis Brevis = Lu-10; Abductor Minimi Digiti = SI-4; 1st Dorsal Interosseus (foot)=LI-3; Tibialis Anterior = Curious Locus; Orbicularis Oculi = GB-I; Frontalis = GB-14; Splenius Capitis = GB-20; Sternocleidomastoid = LI-18; Semi-Spinalis Capitis = BI-10. (b) Good: Opponens Pollicis = Curious Locus; Peroneus Longus = Curious Locus; Flexior Digitorum Longus = Ki-3 (Ki-6); Trapezius (upper) = GB-21; Rectus Abdominis=Ki-15; Vastus Medialis = Sp-10.

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