Despite an increase in anterior knee laxity (AKL) during the adolescent growth spurt in girls, it is unknown whether landing biomechanics are affected by this change. This study investigated whether pubescent girls with higher AKL displayed differences in their lower limb strength or landing biomechanics when performing a horizontal leap movement compared to girls with lower AKL. Forty-six pubescent girls (10-13 years) were tested at the time of their peak height velocity (PHV). Passive AKL was quantified and used to classify participants into higher (HAKL; peak displacement > 4 mm) and lower (LAKL; peak displacement < 3 mm) AKL groups (n = 15/group). Three-dimensional kinematics, ground reaction forces (GRF) and muscle activation patterns were assessed during a horizontal leap landing. HAKL participants displayed significantly (P < 0.05) reduced hip abduction, increased hip abduction moments, as well as earlier hamstring muscle and later tibialis anterior activation compared to LAKL participants. Girls with HAKL displayed compensatory landing biomechanics, which are suggested to assist the functional stability of their knees during this dynamic task. Further research is warranted, however, to confirm or refute this notion.

2014-03-01·Medicine & Science in Sports & Exercise2区 · 医学

The Muscle Stretch Reflex throughout the Menstrual Cycle

2区 · 医学

Article

作者: Yasin Y. Dhaher ; Farah Hameed ; Ellen Casey

INTRODUCTIONThe significant sex disparity in sports-related knee injuries may be due to underlying differences in motor control. Although the development of sex-specific movement patterns is likely multifactorial, this study specifically focuses on the potential modulatory role of sex hormones.PURPOSEThis study aimed to investigate the muscle stretch reflex (MSR) across the menstrual cycle. We hypothesized that the MSR would fluctuate throughout the menstrual cycle and that the lowest response would correspond with peak concentrations of estrogen.METHODSNineteen healthy women age 18-35 yr participated in this study: 8 eumenorrheic women and 11 women taking oral contraceptives. Serum estradiol and progesterone concentrations, anterior knee laxity (AKL), and the MSR response of the quadriceps muscles were measured three times during the menstrual cycle.RESULTSThe MSR response of the rectus femoris (RF) varied significantly across the menstrual cycle in both groups. Specifically, the RF MSR response was 2.4 times lower during the periovulatory phase when compared with the luteal phase (P = 0.007). The same trend was seen in the vastus medialis, but this did not reach statistical significance (P = 0.070). The MSR response of the vastus lateralis did not change significantly across the menstrual cycle (P = 0.494). A mixed model comparison did not show an association between endogenous concentrations of estradiol and progesterone, exposure to hormonal contraceptives or AKL, and the MSR response for any muscle.CONCLUSIONSOur results demonstrate that the RF MSR response varies throughout the menstrual cycle with the lowest response around the time of ovulation. Additional research is needed to clarify the exact relationship between sex hormones, AKL, and MSR response and to determine the specific origin of the change along the monosynaptic reflex arc.

2012-07-01·Supportive Care in Cancer2区 · 医学

Topical amitriptyline, ketamine, and lidocaine in neuropathic pain caused by radiation skin reaction: a pilot study

2区 · 医学

Article

作者: Bev Gerbis ; Dan Gillis ; Isabella Uzaraga ; Eleanor Holwerda ; Elaine Wai

PURPOSEThe purpose of this study is to assess the effect of topical amitriptyline, ketamine, and lidocaine (AKL) on alleviation of neuropathic pain from radiation dermatitis and the feasibility of a randomized trial.MATERIALS AND METHODSEligible subjects had radiation dermatitis with dry or moist desquamation with neuropathic pain and were intolerant or allergic to standard intervention. AKL was applied to painful sites three times a day daily until 2 weeks post-radiotherapy. Subjects were monitored every 2-5 days during radiotherapy and at 2 and 6 weeks after completion of radiotherapy. The University of Washington Neuropathic Pain Scale was used to grade the neuropathic pain before and after use of the interventional gel. Compliance was assessed by asking subjects at each visit how frequently they were using the interventional gel.RESULTSOver a 14-month period, 16 subjects met eligibility criteria. Eighty-two percent of subjects used the AKL as directed. Five subjects (32%) reported fatigue, and three subjects (19%) reported site irritation from the interventional gel. AKL was shown to significantly reduce (p < 0.05) pain intensity, sharpness, burning, sensitivity, itchiness, unpleasantness, deepness, and surfaceness levels on a short-term basis (i.e., between pre-treatment and 30 min post-treatment). AKL was shown to significantly reduce (p < 0.05) burning levels on a long-term basis (i.e., between pre-treatment and 2 weeks post-treatment).CONCLUSIONSAKL was a safe intervention to use with minimal toxicity and good compliance. It significantly reduced several measures of neuropathic pain associated with radiation dermatitis. A larger-scale study would require recruitment from multiple centers.

100 项与 AKL-2 相关的药物交易

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