Elizabeth S Chumanov’s research while affiliated with University of Wisconsin–Madison and other places

Pregnancy and childbirth are associated with increased inter-recti distance (IRD)/diastasis recti abdominis (DRA), pelvic joint laxity, and decreased physical activity levels. Recreational running is an accessible, popular form of exercise that may challenge pelvic stability in postpartum women. To assess the impact of an 8-week abdominal muscle retraining program on IRD and pelvic running mechanics in women up to 2 years postpartum. Pre/posttest single-arm intervention study. Thirteen postpartum women (32.8 ± 2.7 years of age; 1-3 pregnancies; 7 weeks to 2 years postpartum) who were recreational runners participated. Ultrasound imaging measured IRD above and below the umbilicus. Thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles was assessed with ultrasonography at rest and during performance of an abdominal draw-in maneuver. Participants underwent an 8-week abdominal muscle retraining program utilizing ultrasonography as biofeedback. Running gait was assessed with 3-dimensional motion capture at study enrollment (baseline), end of the intervention, and 6-week follow-up. Inter-recti distance below the umbilicus decreased from baseline to end of intervention (P = .013) and remained stable at follow-up (P = .459). Inter-recti distance above the umbilicus, IO and TrA activation ratio, and running mechanics did not change (P > .05). Women reported increased running speed following the intervention (P = .021). An 8-week abdominal muscle retraining program reduced IRD below the umbilicus in recreational runners up to 2 years postpartum, suggesting therapeutic exercise may be part of conservative management for DRA.

Background With a recent increase in running popularity, more women choose to run during and after pregnancy. Little research has examined exercise behaviors and postpartum health conditions of runners. Hypothesis Antenatal and postpartum exercise is beneficial in reducing certain postpartum health conditions. Study Design Cross-sectional study. Level of Evidence Level 5. Methods A self-administered, online survey was developed that consisted of questions regarding antenatal and postpartum exercise behaviors, maternal history, and postpartum health conditions. The survey was completed by 507 postpartum women who were running a minimum of once per week. Results Seventy-two percent of participants ran regularly during pregnancy, with 38% reporting running in the third trimester. Women with musculoskeletal pain during pregnancy were more likely to experience pain on return to running postpartum (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.64-5.88). A birth spacing of <2 years or a vaginal-assisted delivery increased the odds of postpartum stress urinary incontinence (OR, 1.71; 95% CI, 1.00-2.91 and OR, 2.08; 95% CI, 1.24-3.47, respectively), while Caesarean section delivery decreased the odds (OR, 0.58; 95% CI, 0.35-0.96). Multiparous women and those who reported a Caesarean section delivery were more likely to report abdominal separation (OR, 2.11; 95% CI, 1.08-4.26 and OR, 2.20; 95% CI, 1.05-4.70, respectively). Antenatal weight training decreased the odds of postpartum pain (OR, 0.52; 95% CI, 0.28-0.94), stress urinary incontinence (OR, 0.46; 95% CI, 0.21-0.98), and abdominal separation (OR, 0.51; 95% CI, 0.26-0.96). Conclusion Musculoskeletal pain, stress urinary incontinence, and abdominal separation are prevalent conditions among postpartum runners and are more likely to occur with specific maternal history characteristics. Antenatal weight training may reduce the odds of each of these conditions. Clinical Relevance Strengthening exercises during pregnancy may prevent weakening and dysfunction of the abdominal and pelvic floor muscles, decreasing the odds of pain, stress urinary incontinence, and abdominal separation after pregnancy.

Proximal biceps femoris musculotendon strain injury has been well established as a common injury among athletes participating in sports that require sprinting near or at maximum speed; however, little is known about the mechanisms that make this muscle tissue more susceptible to injury at faster speeds. Quantify localized tissue strain during sprinting at a range of speeds. Biceps femoris long head (BFlh) musculotendon dimensions of 14 athletes were measured on magnetic resonance (MR) images and used to generate a finite element computational model. The model was first validated through comparison with previous dynamic MR experiments. After validation, muscle activation and muscle-tendon unit length change were derived from forward dynamic simulations of sprinting at 70%, 85% and 100% maximum speed and used as input to the computational model simulations. Simulations ran from mid-swing to foot contact. The model predictions of local muscle tissue strain magnitude compared favorably with in vivo tissue strain measurements determined from dynamic MR experiments of the BFlh. For simulations of sprinting, local fiber strain was non-uniform at all speeds, with the highest muscle tissue strain where injury is often observed (proximal myotendinous junction). At faster sprinting speeds, increases were observed in fiber strain non-uniformity and peak local fiber strain (0.56, 0.67 and 0.72, for sprinting at 70%, 85% and 100% maximum speed). A histogram of local fiber strains showed that more of the BFlh reached larger local fiber strains at faster speeds. At faster sprinting speeds, peak local fiber strain, fiber strain non-uniformity and the amount of muscle undergoing larger strains are predicted to increase, likely contributing to the BFlh muscle's higher injury susceptibility at faster speeds.

Increasing step rate has been shown to elicit changes in joint kinematics and kinetics during running, and has been suggested as a possible rehabilitation strategy for runners with patellofemoral pain. The purpose of this study was to determine how altering step rate affects internal muscle forces and patellofemoral joint loads, and then to determine what kinematic and kinetic factors best predict changes in joint loading. We recorded whole body kinematics of 30 healthy adults running on an instrumented treadmill at three step rate conditions (90%, 100%, and 110% of preferred step rate). We then used a 3D lower extremity musculoskeletal model to estimate muscle, patellar tendon, and patellofemoral joint forces throughout the running gait cycles. Additionally, linear regression analysis allowed us to ascertain the relative influence of limb posture and external loads on patellofemoral joint force. Increasing step rate to 110% of preferred reduced peak patellofemoral joint force by 14%. Peak muscle forces were also altered as a result of the increased step rate with hip, knee and ankle extensor forces, and hip abductor forces all reduced in mid-stance. Compared to the 90% step rate condition, there was a concomitant increase in peak rectus femoris and hamstring loads during early and late swing, respectively, at higher step rates. Peak stance phase knee flexion decreased with increasing step rate, and was found to be the most important predictor of the reduction in patellofemoral joint loading. Increasing step rate is an effective strategy to reduce patellofemoral joint forces and could be effective in modulating biomechanical factors that can contribute to patellofemoral pain.

Case report. Postpartum low back and hip dysfunction may be caused by an incomplete recovery of abdominal musculature and impaired neuromuscular control. The purpose of this report is to describe the management of a postpartum runner with hip and low back pain through exercise training via ultrasound imaging (USI) biofeedback combined with running-form modification. A postpartum runner with hip and low back pain underwent dynamic lumbar stabilization training with USI biofeedback and running-form modification to reduce mechanical loading. Muscle thickness of transversus abdominis and internal oblique was measured with USI preintervention and 7 weeks after completion of the intervention. Additionally, 3-dimensional lower extremity joint motions, moments, and powers were calculated during treadmill running. The patient's pain with running decreased from a constant 9/10 (0, no pain; 10, worst pain) to an occasional 3/10 posttreatment. Transversus abdominis muscle thickness increased 6.3% during the abdominal drawing-in maneuver and 27.0% during the abdominal drawing-in maneuver with straight leg raise. Changes were also noted in the internal oblique. These findings corresponded to improved lumbopelvic control: pelvic list and axial rotation during running decreased 38% and 36%, respectively. The patient's running volume returned to preinjury levels (8.1-9.7 km, 3 days per week) with no hip pain and minimal low back pain, and she successfully completed her goal of running a half-marathon. The successful outcomes of this case support the consideration of dynamic lumbar stabilization exercises, USI biofeedback, and running-form modification in postpartum runners with lumbopelvic dysfunction. Therapy, level 4.

Running with a step rate 5-10% greater than one's preferred can substantially reduce lower extremity joint moments and powers, and has been suggested as a possible strategy to aid in running injury management. The purpose of this study was to examine how neuromuscular activity changes with an increase in step rate during running. Forty-five injury-free, recreational runners participated in this study. Three-dimensional motion, ground reaction forces, and electromyography (EMG) of 8 muscles (rectus femoris, vastus lateralis, medial gastrocnemius, tibialis anterior, medial and lateral hamstrings, and gluteus medius and maximus) were recorded as each subject ran at their preferred speed for three different step rate conditions: preferred, +5% and +10% of preferred. Outcome measures included mean normalized EMG activity for each muscle at specific periods during the gait cycle. Muscle activities were found to predominantly increase during late swing, with no significant change in activities during the loading response. This increased muscle activity in anticipation of foot-ground contact likely alters the landing posture of the limb and the subsequent negative work performed by the joints during stance phase. Further, the increased activity observed in the gluteus maximus and medius suggests running with a greater step rate may have therapeutic benefits to those with anterior knee pain.

It is well recognised that the hamstrings are susceptible to acute strain injury during high-speed running. However, the particular phase of the sprinting gait cycle at which hamstring injury occurs remains a debated topic. Video footage and athlete anecdotes have contributed to the discussion, but do not provide sufficient temporal resolution to fully answer the question. In this paper, we briefly review: (A) biomechanical data obtained from healthy athletes; (B) case studies of injuries during biomechanical experiments; and (C) clinical outcomes from intervention studies. We believe all of these support the premise that late swing phase is the likely time when the biarticular hamstrings are most vulnerable to injury. Early …