respect to the stance of a live batter and the bounce of the new ball. The batter “took guard” on the line of middle stump and stood with feet parallel and either side of the popping crease. A live batter was included for 2 primary reasons: to provide specific cues for the bouncer (short-pitched delivery
Simon A. Feros, Warren B. Young and Brendan J. O’Brien
Lachlan E. Garrick, Bryce C. Alexander, Anthony G. Schache, Marcus G. Pandy, Kay M. Crossley and Natalie J. Collins
force vector is medial to the knee joint center throughout stance, hence an external knee adduction moment (KAM) is generated. However, with excessive dynamic knee valgus, the ground reaction force vector may (in extreme cases) shift lateral to the knee joint center in the frontal plane, thereby
Mason D. Smith and David R. Bell
Anterior cruciate ligament (ACL) reconstruction is the standard of care for individuals with ACL rupture. Balance deficits have been observed in patients with ACL reconstruction (ACLR) using advanced posturography, which is the current gold standard. It is unclear if postural-control deficits exist when assessed by the Balance Error Scoring System (BESS), which is a clinical assessment of balance.
The purpose of this study is to determine if postural-control deficits are present in individuals with ACLR as measured by the BESS.
Thirty participants were included in this study. Fifteen had a history of unilateral ACLR and were compared with 15 matched controls.
The BESS consists of 3 stances (double-limb, single-limb, and tandem) on 2 surfaces (firm and foam). Participants begin in each stance with hands on their hips and eyes closed while trying to stand as still as possible for 20 s.
Main Outcome Measures:
Each participant performed 3 trials of each stance (18 total), and errors were assessed during each trial and summed to create a total score.
We observed a significant group × stance interaction (P = .004) and a significant main effect for stance (P < .001). Post hoc analysis revealed that the ACLR group had worse balance on the single-leg foam stance than did controls. Finally, the reconstructed group had more errors when total BESS score was examined (P = .02).
Balance deficits exist in individuals with ACLR as measured by the BESS. Total BESS score was different between groups. The only condition that differed between groups was the single-leg stance on the unstable foam surface.
Fatemeh Azadinia, Ismail Ebrahimi-Takamjani, Mojtaba Kamyab, Morteza Asgari and Mohamad Parnianpour
.1016/j.clinbiomech.2009.05.004 10.1016/j.clinbiomech.2009.05.004 Della Volpe , R. , Popa , T. , Ginanneschi , F. , Spidalieri , R. , Mazzocchio , R. , & Rossi , A. ( 2006 ). Changes in coordination of postural control during dynamic stance in chronic low back pain patients . Gait & Posture
Max Pietrzak and Niels B.J. Vollaard
single limb from each subject (Figure 1 ). In order to avoid effects of intervention order and/or limb dominance, the treatment order was counterbalanced with 7 subjects having the stance leg treated first and the remaining 6 subjects receiving treatment on the skill leg first, the skill leg defined as
Beth Jamali, Martha Walker, Brian Hoke and John Echternach
Windlass taping is used to reduce pain in plantar fasciitis and thought to take stress off the plantar fascia.
To investigate the effects of windlass taping.
Single group, repeated measures.
Outpatient physical therapy clinics.
20 subjects with plantar fasciitis.
Windlass taping technique.
Main Outcome Measures:
Pretaping and posttaping measures included pain levels using a visual analog scale (VAS), resting-stance calcaneal position, tibial position, and navicular height. Fifteen also reported a VAS after wearing the tape for 24 h.
Median VAS score 37 mm pretape and 6 mm immediately posttape and 24 h later. Wilcoxon matched-pairs signed ranks test significant (P = .001) for reduction in pain scores. Paired t tests significant (P = .01) for a difference between means of pretaping and posttaping measurements for resting-stance positions.
Windlass taping decreased pain in patients with plantar fasciitis and caused small changes in resting-stance positions.
Bryan L. Riemann, Kevin M. Guskiewicz and Edgar W. Shields
Although sophisticated forceplate systems are available for postural stability analyses, their use is limited in many sports medicine settings because of budgetary constraints. The purpose of this investigation was to compare a clinical method of evaluating postural stability with a force-platform sway measure. Participants completed a battery of three stance variations (double, single, and tandem) on two different surfaces (firm and foam) while standing on a force platform. This arrangement allowed for simultaneous comparisons between forceplate sway measures and clinical assessments using the Balance Error Scoring System (BESS). Significant correlations were revealed for the single-leg and tandem stances on the firm surface and for double, single, and tandem stances on the foam surface. These results suggest that the BESS is a reliable method of assessing postural stability in the absence of computerized balance systems.
Becky L. Heinert, Thomas W. Kernozek, John F. Greany and Dennis C. Fater
To determine if females with hip abductor weakness are more likely to demonstrate greater knee abduction during the stance phase of running than a strong hip abductor group.
Observational prospective study design.
University biomechanics laboratory.
15 females with weak hip abductors and 15 females with strong hip abductors.
Main Outcome Measures:
Group differences in lower extremity kinematics were analyzed using repeated measures ANOVA with one between factor of group and one within factor of position with a significance value of P < .05.
The subjects with weak hip abductors demonstrated greater knee abduction during the stance phase of treadmill running than the strong group (P < .05). No other significant differences were found in the sagittal or frontal plane measurements of the hip, knee, or pelvis.
Hip abductor weakness may influence knee abduction during the stance phase of running.
Thomas A. Stoffregen, Philip Hove, Jennifer Schmit and Benoît G. Bardy
We demonstrated that postural responses to imposed optic flow are to some extent voluntary. In a moving room, participants either stood normally or were instructed to resist any influence of visible motion on their stance. When participants attempted to resist, coupling of body sway with motion of the room was significantly greater than when the eyes were closed, but was significantly reduced relative to coupling in the normal stance condition. The results indicate that the use of imposed optic flow for postural control is not entirely automatic or involuntary. This conclusion motivates a search for non-perceptual factors that may influence the degree to which body sway is coupled to imposed optic flow.
Michael Sanders, Anton E. Bowden, Spencer Baker, Ryan Jensen, McKenzie Nichols and Matthew K. Seeley
requirements for the left leg during terminal stance and initial ground contact, respectively. Based on these results, we expect the following muscular adaptations for traditional crutch ambulation regarding EMG for ambulation involving traditional crutches: hypertrophy or at least muscle mass maintenance for