Physical Therapy

Relationship between Range of Motion, Strength, Upper Quarter Y-balance Test and a history of Shoulder Injury among NCAA Division I Overhead Athletes

Background: Several risk factors have been identified as contributors to the development of shoulder injuries, including glenohumeral internal rotation deficit, rotator cuff weakness, and shoulder instability. However, lasting deficits of the physical characteristics among overhead athletes with a history of a shoulder injury are unknown. Objective: To compare shoulder range of motion (ROM), strength, and upper-quarter dynamic balance between collegiate overhead athletes with and without a history of a shoulder injury. Methods: 58 overhead athletes were distributed into a shoulder injury history group (n=25) and healthy group (n=33). All participants were fully participating in NCAA Division I baseball, softball, volleyball, or tennis and free of any symptoms of shoulder injuries. An investigator measured active ROM for dominant shoulder internal rotation (IR), external rotation (ER), and horizontal adduction (HAD) using a digital inclinometer. Isometric strength for dominant shoulder IR and ER at 90° of abduction was measured using a hand-held dynamometer. The upper quarter dynamic balance was assessed via the Upper Quarter Y-Balance Test (UQYBT). Results: The injury group demonstrated a lower UQYBT mean score in the superolateral direction. However, there were no statistically significant intergroup differences in shoulder ROM, strength, ER/IR strength ratio, and UQYBT in the medial direction and inferolateral direction. Conclusions: Overhead athletes with a previous history of shoulder injury had poorer UQYBT in the superolateral direction despite a lack of ongoing symptoms or deficits in function. Well-planed dynamic balance training and related strengthening exercises may be warranted for overhead athletes to improve their upper quarter functions.
Listed In: Physical Therapy, Sports Science, Other

Association of isometric hip and ankle strength with frontal plane kinetics in females during running

Frontal plane mechanics have been associated with running-related injuries such as patellofemoral pain. Strengthening and gait retraining programs aimed at reducing hip adduction during running have been shown to be effective at alleviating symptoms, however evidence of their effect on running kinematics is equivocal. It is possible that such programs exert their benefits through altering kinetics rather than kinematics in the frontal plane during running. Further, the contributions of the ankle to frontal plane mechanics have not been well studied. PURPOSE: To determine if hip and ankle strength are associated with frontal plane kinetics in female runners. METHODS: 64 healthy women running at least 16km per week participated in this study. Isometric hip abduction and ankle inversion strength were measured using a handheld dynamometer. 3D gait analysis was conducted as participants ran on an instrumented treadmill at 2.7 m/s. Participants were ranked in order of isometric strength of both the hip and ankle, and divided into tertiles of high, medium and low strength. 2-way MANOVA was used to determine the relationship between strength and peak moment, positive work and negative work in the frontal plane of the hip and the ankle. Tukey post-hoc tests were conducted where applicable (α=0.05). RESULTS: There was no significant interaction effect, or main effect of hip strength. There was a significant main effect of ankle strength on frontal plane kinetics (p=0.024). Specifically, the strong ankle group compared to the weak ankle group had significantly greater magnitude of peak ankle inversion moment (0.95(0.32) vs 0.68(0.22) Nm/kg, p=0.033), hip abduction moment (-2.78(1.02) vs -1.88(0.24) Nm/kg, p=0.002) and hip frontal plane positive work (0.27(0.19) vs. 0.13(0.03) W/kg, p=0.006). CONCLUSION: Isometric ankle but not hip strength is associated with kinetics in the frontal plane during running in females. Thus ankle strength should not be overlooked in clinical evaluation and treatment of runners.
Listed In: Biomechanics, Gait, Physical Therapy, Sports Science

Static Foot Structure May Predict Midfoot Mechanics

INTRODUCTION: Clinical interventions for foot injury prevention are often prescribed based on static measures of foot structure. However, this convention merits further investigation as the static-dynamic relationship has only been explored in walking and running. The primary aim of this study was to explore the relationship between static foot structure and dynamic midfoot kinematics and kinetics during a barefoot single-leg landing. METHODS: 48 females (age=20.4±1.8 yr, height=1.6±0.06 m, weight=57.3±5.5 kg) completed the study. Standing arch height index (AHI) was measured using the Arch Height Index Measurement System. Skin markers were attached using a multi-segment foot model by Bruening et al.1 A14-camera motion capture system (Vicon) was used to sample kinematic data at 250Hz while two force platforms (AMTI) sampled kinetic data at 1000Hz. A static trial was captured then subjects hung from wooden rings and performed barefoot single-leg drop landings from a height of 0.4m. Metrics were calculated in Visual 3D (C-motion, Inc.) to obtain static midfoot angle (MA), midtarsal range of motion (ROM), and midtarsal work. PCCs were calculated for static and dynamic variables using paired t-tests in SAS. RESULTS: AHI was correlated negatively with sagittal plane midtarsal ROM (r=-0.32032, p=0.0264) and positively with midtarsal work (r=0.33180, p=0.0212). MA was correlated positively with sagittal plane midtarsal ROM (r=0.48336, p=0.0005) and negatively with midtarsal work (r=-0.32321, p=0.0250). DISCUSSION/CONCLUSION: Static foot structure may be a valuable clinical tool in assessing midfoot function relating to injury risk in athletes, who participate in high-impact loading activities, as well as in pathological populations.
Listed In: Biomechanics, Orthopedic Research, Physical Therapy, Sports Science

Examining Postural Control With and Without Visual Feedback in Individuals with history of Ankle Sprain

Lateral ankle sprains are common orthopedic injuries and often result in chronic ankle instability (CAI). Studies have shown that the CAI population typically has decreased ankle proprioception and possibly a greater reliance on visual feedback when compared to healthy controls. However, little is known about how the postural control characteristics change in those with and without CAI when external visual feedback is manipulated. Purpose: To compare postural control characteristics of persons with CAI, Copers and healthy adults when performing a single leg balance test with and without external feedback. Method: The definition for CAI used for this study includes persons who have experienced recurrent ankle sprains, in addition to self-reported “feelings of instability” and “giving way,” and a score on the Identification of Functional Ankle Instability (IdFAI) of 11 or greater. 18 participants with CAI, 15 Copers, and 18 healthy controls (mean age of all groups: 22 years) performed the Athlete Single Leg Test on the Biodex Balance System (BBS) at Level 4 which involved a high degree of platform instability. All participants completed 2 trials without and with feedback in that order. Center of pressure position was recorded and the two trial mean was used for further analysis. Overall stability index (OSI) defined as the mean distance of the center of pressure from the center of the platform was obtained from the system. Sway area was calculated using custom Matlab script. Separate 3 (Group) x 2 (Feedback) mixed ANOVAs were run using overall stability index (OSI), and sway area as dependent variables. Results: Significant feedback main effect showed participants had significantly lower (better) OSI value with feedback (1.4±0.1) compared to without feedback (2.6±0.2; P < 0.001) but sway area with feedback (8.61±2.33cm2) was similar to without feedback (10.94±2.43 cm2). There was no significant group main effect or interaction observed for either of the variables. Conclusion: Results suggest that external visual feedback may not play a significant role in helping persons with CAI improve their postural control.
Listed In: Orthopedic Research, Physical Therapy

Head Acceleration During Girls Youth Soccer Using Real Time Data

Title:  Head Acceleration During Girls Youth Soccer Using Real Time Data   Emily Messerschmidt, Katlyn Van Patten, Ryan Lee, Srikant Vallabhajosula Purpose/Hypothesis: While the acute effects of concussion have been the focus of research in the past, there is a new emphasis toward following the cumulative effects of sub-concussive head accelerations in athletics. This is especially important in youth athletes because the developing brain is more vulnerable to injury from head trauma in sports like soccer due to techniques such as heading, that can result in numerous head impacts throughout play. There is a current lack of evidence on the magnitude and frequency of head accelerations that occur during real-time youth sports, including soccer, and whether these accelerations have a detrimental cumulative effect. The purpose of the current study was to measure the head acceleration that youth athletes experience during real-time soccer games.   Number of Subjects: 31 under-15 girls club soccer participants. 11 players monitored each game.   Materials/Methods: 3 season games were observed. Triax Smart Impact Monitor headband accelerometers were worn during gameplay to collect real-time head impact data. Forces >10g were recorded. Games were video recorded for further analysis. Head impacts were categorized by type of impact: purposeful header (PH), player to player (PP), player to ground (PG), and ball to head (BH). Data was analyzed using descriptive statistics.   Results: A total of 171 impacts were observed (PH=20, PP=113, PG=36, BH=2). Only one impact recorded was above the concussion threshold of 70g. The majority (77%) of impacts observed were <10g. Of the accelerations recorded, PH resulted in the largest average acceleration (36.8±14.9g) followed by PG (20.5±4.2g), and PP (19.5±4.6g). The maximum accelerations for PH, PG and PP were 73g, 26g and 30g respectively. No BH accelerations were recorded >10g.   Conclusions: While PH yielded the highest average acceleration, it was one of the least frequently occurring impacts. PP impacts were most common however the majority produced little to no head acceleration. While there was variability of head acceleration that occurred within each type of impact, none produced consistently dangerous (≥70g) accelerations. Clinical Relevance: This study provides preliminary evidence of the impacts sustained during girls youth soccer games for athletic trainers or sports physical therapists who are monitoring athletes for concussions. The findings reveal that the use of headband accelerometers to measure real-time data can be a useful tool to monitor multiple players on the field. There remains a need for further research into the effect of cumulative sub-concussive impacts during soccer in youth athletes with larger sample size. Further studies should investigate the impacts players sustain over multiple seasons to observe if those who experience multiple sub-concussive impacts report concussion-like symptoms or show concussion-like signs. Additionally, this study adds evidence to the existing literature that the use of video analysis to confirm the occurrence of impacts and to correctly categorize them is highly beneficial to ensure reliability in future studies.
Listed In: Biomechanics, Physical Therapy, Sports Science

Effects of an 8-week cadence gait training program on knee loading in individuals following ACL reconstruction

While normalization of gait is a primary goal of early rehabilitation, between limb asymmetries in knee extensor moment can persist 6-24 months later and previous literature assessing gait interventions is limited. The purpose of this study was to assess the influence of subject-specific cadence gait training program on knee loading mechanics following ACLr. Nine individuals completed an 8-week cadence training program (20min, 3x/week; Table1) and nine sex- and surgery-matched individuals served as controls. All eighteen participants received standard physical therapy and were tested at 1 and 3 months post-op. Kinematic and kinetic data were collected during walking at a self-selected speed. Repeated measures ANOVAs were used for comparisons; significance α≤0.05. Main effects of limb and time were observed: knee ROM (kROM;p<0.001;p=0.044;Fig.1) and knee extensor moment (kEXT;p=0.003;p=0.002) in the cadence and control groups, respectively. No main effects of group for kROM (p=0.136) or kEXT (p=0.229) were found. A trend toward a significant group x time x limb interaction was observed in kEXT (p=0.092), but not kROM (p=0.412). Post-hoc analyses of kEXT (Fig.2) revealed a significant time x limb interaction for the cadence group (p=0.053) but not the control group (p=0.884). In the cadence group, the time x limb interaction was driven by a 131% increase in kEXT in the surgical limb versus a 42% increase in the non-surgical limb between T1 and T2. Consistent with previous findings, these pilot data show promising results as the cadence intervention resulted in improvements in sagittal plane knee loading compared to controls.

Listed In: Biomechanics, Gait, Orthopedic Research, Physical Therapy, Sports Science

Pushoff Work is Increased Following Prosthesis Adaptation

The purpose of this study was to quantify adaptation to a new prosthesis in terms of mechanical work profiles. Currently, there is a lack of knowledge on how individuals adapt to a new prosthesis, with many studies investigating different prosthetic feet but not adaptation over time. Thus, there is a need for objective measures to quantify the process of adaptation. Mechanical power and work profiles are a prime subject for modern energy-storage-and-return type prostheses, as the amount of energy a prosthesis stores and returns (i.e., positive and negative work) during stance is directly related to how a user loads and unloads the limb. 22 individuals with unilateral, transtibial amputation were given a new prosthesis at their current mobility level (K3 or above) and wore it for a three-week adaptation period. Kinematic and kinetic measures were recorded from walking on overground force plates at 0, 1.5, and 3 weeks into the adaptation period. Positive and negative work done by the prosthesis and intact ankle-foot was calculated using a unified deformable segment model. Positive work from the prosthesis side increased by 6.1% and intact side by 5.7% after 3 weeks (p = .041, .036). No significant changes were seen in negative power from prosthesis or intact side (p = .115, .192). Analyzing work done by a prosthesis may be desirable for tracking a patient’s gait rehabilitation over time. Future work may analyze how mechanical work profiles relate to more traditional clinical measures.

Listed In: Biomechanics, Gait, Physical Therapy

Differences In Core Stability Between Collegiate Football Players With And Without Shoulder Pain

The purpose of this study was to determine differences in core stability between collegiate football players with and without non-traumatic shoulder pain. 20 collegiate football players completed tests of trunk control and muscle capacity. Control was assessed via an unstable chair placed on a force plate. Static control was assessed by center of pressure movement during seated balance using 95% confidence ellipse area (CEA; mm2) and mean velocity (MVEL; mm/s). Dynamic control was assessed during a speed and accuracy target acquisition task. Directional control (DC; mm; COP path to target) and precision control (movement around target prior to acquisition (PC; CEA mm2)) were measured. Capacity was assessed by trunk flexor (FLEX; s) and extensor endurance (EXT; s) and double-leg lowering (DLL; °). MANOVA (Eta) and t-tests (Cohen’s d) assessed group differences (p < 0.05) Core stability was not significantly different between groups. Data presented as mean ± stdev (No Pain/Pain), p-value, effect size: Static control- CEA 183 ± 129/ 131 ± 85 and MVEL 5.7 ± 3.0/6.4 ± 2.6, p = 0.38, Eta =.33; Dynamic Control- DC 49± 9/46 ± 6, p = 0.49, d =.39 and PC 143 ± 72/93± 25, p = 0.051, d = 0.93; Capacity: FLEX 77 ± 38/99 ± 32, EXT 74 ± 22/69± 28, p = 0.22, Eta= .40 and DLLT 14 ± 10/15 ± 11, p = 0.92, d =.05. Our data do not provide evidence of diminished core stability in football players with shoulder pain.

Listed In: Biomechanics, Physical Therapy

Immediate Effects of Vibrotactile Feedback on Postural Sway in Healthy Older Adults

Previous research has shown the utility of vibrotactile feedback to improve postural sway characteristics in persons with vestibular deficits. Tactile feedback given through vibration has been used more as a modality of training but immediate effects on postural control among older adults have not been investigated. PURPOSE: To compare the immediate effects of tactile vibration on postural sway in healthy older adults in challenging stance and sensory conditions. METHODS: 10 healthy older adults (76.4 ± 6.8years), performed five standing balance conditions on a AMTI forceplate for 30s each: feet together on firm surface eyes open (C1), eyes closed (C2); feet together on foam surface eyes open (C3), eyes closed (C4), and tandem stance on firm surface eyes open (C5). Participants did 2 trials of each condition both with and without vibrotactile feedback. The feedback was given using a waist belt with sensors that were activated when participants swayed in a particular direction as detected by an Xbox Kinect camera (Sensory Kinetics system; Engineering Acoustics, Casselberry, FL). Center of pressure sway area was compared within each condition using a paired samples t-test to estimate the effect of vibration. RESULTS: See Table 1. Since only 5 subjects could complete C4 data was not included in statistical analysis. CONCLUSION: Tactile vibration did not acutely effect postural sway in challenging stance conditions in healthy older adults. Long term effects of tactile vibration on postural sway in challenging stance conditions need to be investigated.
Listed In: Physical Therapy

Dance May Improve Quality of Life But Not Gait in Individuals with Parkinson’s Disease

Purpose: Research supports the use of ballroom dance to improve balance in individuals with Parkinson’s disease (PD). This study used the Mark Morris Dance for PD program as a template for dance classes to examine the effects of dance on gait, balance, and quality of life in individuals with PD. Subjects : Eleven individuals with mild to moderate PD participated in the study. Methods : A trained instructor led dance classes for subjects once a week for 12 weeks. Participants were encouraged to use the Mark Morris Dance for PD At Home DVD twice a week for 45 minutes. Classes included a 20 min. seated warm up; a 20 min. supported standing portion focused on balance and strength; and 30 min. partnered movements for swing, shag, or tango. Data collected before and after the intervention included gait parameters (Protokinetics Zeno walkway), sway area (AMTI force platform) during mCTSIB, Mini-BESTest, Falls Efficacy Scale, Apathy Scale and PDQ-39. A paired-samples t-test was performed. Results : Participants had significant decrease in apathy following the intervention (P = 0.018). A significant decrease in the percentage of the double support phase of gait indicated individuals spent less time with both feet in contact with the ground (P = 0.019). Conclusions : An instructor-led dance class based on the Dance for PD program once per week for 12 weeks improved certain aspects of quality of life, but not necessarily gait and balance. Further research with increased frequency of supervised dance classes is indicated.
Listed In: Gait, Neuroscience, Physical Therapy