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Samuel C. Fischer, Darren Q. Calley, and John H. Hollman
Clinical Scenario : Low back pain is a common condition for the general population with 29% of adults having low back pain within the last 3 months. A deadlift is described as a free weight exercise in which a barbell is lifted from the floor in a continuous motion by extending the knees and hips. For those without low back pain, the deadlift was found to have the highest muscle activation of paraspinal musculature compared with other exercises. There are a limited number of studies that investigate the usefulness of incorporating deadlifts as part of a rehabilitation program for low back pain. Clinical Question: For those who live with low back pain, is an exercise routine that includes a deadlift a viable treatment option to improve pain and/or function? Summary of Key Findings: The literature search yielded 3 total studies meeting the inclusion and exclusion criteria: 1 randomized control trial, 1 secondary analysis of a randomized control trial, and 1 cohort study. Exercise programs that include deadlifts can yield improvements in both pain and function for those living with low back pain but were not found to be more beneficial than low load motor control exercises. Those with lower pain levels and higher baseline lumbar extension strength may be most appropriate to participate in an exercise program that includes deadlifts. Further research is needed to compare exercise programs that include deadlifts to other interventions for those living with low back pain. Clinical Bottom Line: There is minimal evidence that exercise programs that included deadlifts are a clinically effective option for the treatment of low back pain for both pain scores and functional outcome measures. Strength of Recommendation: Level B evidence exists that exercise programs that include deadlifts are a clinically effective option for the treatment of low back pain for both pain scores and functional outcome measures.
David A. Krause, Beth A. Cloud, Lindsey A. Forster, Jennifer A. Schrank, and John H. Hollman
Context:
Limited ankle DF (DF) range of motion (ROM) resulting from restricted gastrocnemius and soleus mobility is associated with a variety of lower extremity pathologies. Several techniques are used clinically to measure ankle DF.
Objectives:
To evaluate the reliability and minimal detectable change of DF ROM measurement, determine whether there is a difference in measured DF between techniques, and quantify the electromyographic (EMG) activity of the soleus and tibialis anterior muscles associated with the techniques.
Design:
Repeated measures.
Setting:
Controlled laboratory setting.
Participants:
39 healthy subjects, age 22–33.
Main Outcome Measures:
DF measurements using 5 different techniques including active and passive DF with the knee extended and flexed to 90° and a modified lunge. EMG activity of the soleus and anterior tibialis muscles.
Results:
Intrarater reliability values (ICC3,1) ranged from .68 to .89. Interrater reliability (ICC2,1) ranged from .55 to .82. ICCs were the greatest with the modified lunge. The minimal detectable change (MDC95) ranged from 6° to 8° among the different techniques. A significant difference in DF ROM was found between all methods. Measurements taken with active DF were greater than the same measures taken passively. The lunge position resulted in greater DF ROM than both active and passive techniques. EMG activity of the soleus was greater with active DF and the lunge than with passive DF.
Conclusions:
The modified lunge, which demonstrated excellent intrarater and interrater reliability, may best represent maximal DF. Active end-range DF was significantly greater than passive end-range DF when measured at either 0° or 90° knee flexion. Greater active DF was not explained by inhibition of the soleus. Finally, using the modified lunge, a difference between 2 measurements over time of 6° or more suggests that a meaningful change has occurred.
John H. Hollman, Nicholas J. Beise, Michelle L. Fischer, and Taylor L. Stecklein
Context: Examining the coordinated coupling of muscle recruitment patterns may provide insight into movement variability in sport-related tasks. Objective: The purpose of this study was to examine the relationship between coupled gluteus maximus and medius recruitment patterns and hip-adduction variability during single-limb step-downs. Design: Cross-sectional. Setting: Biomechanics laboratory. Participants: Forty healthy adults, including 26 women and 14 men, mean age 23.8 (1.6) years, mean body mass index 24.2 (3.1) kg/m2, participated. Interventions: Lower-extremity kinematics were acquired during 20 single-limb step-downs from a 19-cm step height. Electromyography (EMG) signals were captured with surface electrodes. Isometric hip-extension strength was obtained. Main Outcome Measures: Hip-adduction variability, measured as the SD of peak hip adduction across 20 repetitions of the step-down task, was measured. The mean amplitudes of gluteus maximus and gluteus medius EMG recruitment were examined. Determinism and entropy of the coupled EMG signals were computed with cross-recurrence quantification analyses. Results: Hip-adduction variability correlated inversely with determinism (r = −.453, P = .018) and positively with entropy (r = .409, P = .034) in coupled gluteus maximus/medius recruitment patterns but not with hip-extensor strength nor with magnitudes of mean gluteus maximus or medius recruitment (r = −.003, .081, and .035; P = .990, .688, and .864, respectively). Conclusion: Hip-adduction variability during single-limb step-downs correlated more strongly with measures of coupled gluteus maximus and medius recruitment patterns than with hip-extensor strength or magnitudes of muscle recruitment. Examining coupled recruitment patterns may provide an alternative understanding of the extent to which hip neuromuscular control modulates lower-extremity kinematics beyond examining muscle strength or EMG recruitment magnitudes.
James W. Youdas, Erica F. Loder, Jody L. Moldenhauer, Christine R. Paulsen, and John H. Hollman
Context:
Hip-abductor weakness is associated with many lower extremity injuries. A simple procedure to assess hip-abductor performance is necessary in patient populations.
Objective:
To describe the change in pelvic-on-femoral position of the stance limb before and after 45 seconds of resisted sidestepping.
Design:
Cross-sectional comparative.
Setting:
Laboratory.
Participants:
24 healthy women (24.6 ± 3.5 years) and 14 healthy men (24.5 ± 3.0 years).
Main Outcome Measures:
Pelvic-on-femoral position in degrees in single-leg stance before and after 45 seconds of resisted sidestepping.
Results:
The difference between the baseline and postexercise measurements for both men and women was significant (P < .05). The effect of the resisted-sidestepping exercise on the hip abductors was not statistically different between men and women.
Conclusions:
Forty-five seconds of resisted sidestepping using an elastic band produced a change in pelvic-on-femoral position in healthy adults. This test might be useful to detect impaired performance in hip abductors of patients with injury elsewhere in the musculoskeletal system.
John H. Hollman, Kimberly E. Kolbeck, Jamie L. Hitchcock, Jonathan W. Koverman, and David A. Krause
Context:
Hip-muscle weakness might be associated with impaired biomechanics and postures that contribute to lower extremity injuries.
Objective:
To examine relationships between hip-muscle strength, Q angle, and foot pronation.
Design:
Correlational study.
Setting:
Academic laboratory.
Participants:
33 healthy adults.
Main Outcome Measures:
Maximal isometric hip abduction (Abd), adduction (Add), external-rotation (ER) and internal-rotation (IR) strength; Q angle of the knee; and longitudinal arch angle of the foot. We analyzed Pearson product– moment (r) correlation coefficients between the Abd/Add and ER/IR force ratios, Q angle, and longitudinal arch angle.
Results:
The hip Abd/Add force ratio was correlated with longitudinal arch angle (r = .35, P = .025).
Conclusions:
Reduced strength of the hip abductors relative to adductors is associated with increased pronation at the foot. Clinicians should be aware of this relationship when examining patients with lower extremity impairments.
James W. Youdas, Sara T. Mraz, Barbara J. Norstad, Jennifer J. Schinke, and John H. Hollman
Context:
Hip abductor muscle weakness is related to many lower extremity injuries. A simple procedure, the Trendelenburg test, may be used to assess hip abductor performance in patient populations.
Objective:
To describe the minimal detectable change (MDC) in pelvic-on-femoral (P-O-F) position of the stance limb during the Trendelenburg test.
Setting:
Laboratory.
Participants:
45 healthy women (28 ± 8 years) and 45 healthy men (33 ± 11 years).
Main Outcome Measures:
P-O-F position in degrees in single-leg stance. Results: Baseline P-O-F position (hip adduction) was 83° ± 3° with a range from 76° to 94°. The intratester reliability (ICC3,1 for measurement of P-O-F position using a universal goniometer was 0.58 with a standard error of measurement (SEM) of 2°. The minimal detectable change (MDC) was calculated to be 4°.
Conclusions:
If a person’s P-O-F position changes less than 4° between measurements, then the P-O-F position is within measurement error and it can be determined that there has been no change in the performance of the hip abductor muscles when examined by the Trendelenburg test.
James W. Youdas, Timothy J. McLean, David A. Krause, and John H. Hollman
Context:
Posterior calf stretching is believed to improve active ankle dorsiflexion range of motion (AADFROM) after acute ankle-inversion sprain.
Objective:
To describe AADFROM at baseline (postinjury) and at 2-wk time periods for 6 wk after acute inversion sprain.
Design:
Randomized trial.
Setting:
Sports clinic.
Participants:
11 men and 11 women (age range 11–54 y) with acute inversion sprain.
Intervention:
Standardized home exercise program for acute inversion sprain.
Main Outcome Measure:
AADFROM with the knee extended.
Results:
Time main effect on AADFROM was significant (F 3,57 = 108, P < .001). At baseline, mean active sagittal-plane motion of the ankle was 6° of plantar flexion, whereas at 2, 4, and 6 wk AADFROM was 7°, 11°, and 11°, respectively.
Conclusions:
AADFROM increased significantly from baseline to week 2 and from week 2 to week 4. Normal AADFROM was restored within 4 wk after acute inversion sprain.
John H. Hollman, Jeffrey M. Hohl, Jordan L. Kraft, Jeffrey D. Strauss, and Katie J. Traver
Context:
Abnormal lower extremity kinematics during dynamic activities may be influenced by impaired gluteus maximus function.
Objective:
To examine whether hip-extensor strength and gluteus maximus recruitment are associated with dynamic frontal-plane knee motion during a jump-landing task.
Design:
Exploratory study.
Setting:
Biomechanics laboratory.
Participants:
40 healthy female volunteers.
Main Outcome Measures:
Isometric hip-extension strength was measured bilaterally with a handheld dynamometer. Three-dimensional hip and knee kinematics and gluteus maximus electromyography data were collected bilaterally during a jumplanding test. Data were analyzed with hierarchical linear regression and partial correlation coefficients (α = .05).
Results:
Hip motion in the transverse plane was highly correlated with knee motion in the frontal plane (partial r = .724). After controlling for hip motion, reduced magnitudes of isometric hip-extensor strength (partial r = .470) and peak gluteus maximus recruitment (partial r = .277) were correlated with increased magnitudes of knee valgus during the jump-landing task.
Conclusion:
Hip-extensor strength and gluteus maximus recruitment, which represents a measure of the muscle’s neuromuscular control, are both associated with frontal-plane knee motions during a dynamic weight-bearing task.
