M.Tech. (Chiropractic) / Problem Statement: Ankle sprains are one of the most common acute injuries treated by physicians (Pellow & Brantingham, 2001). Most ankle sprains involve the lateral ankle ligaments, with the anterior tibiotalar ligament being the most commonly affected in injuries involving plantarflexion and inversion. These injuries often result in restriction of movements that will limit gait (Crosbie, Green, Refshauge, 1999). Even in the event of injury to one ankle, the sensorimotor and postural deficits can be bilateral due to central processing of motor control information (Munna et. al., 2010, Monaghan et. al., 2006). The primary aim of a chiropractic adjustment is to increase joint range of motion (Fryer, Mudge, McLaughlin, 2002) and to correct local joint dysfunction (Pellow & Brantingham, 2001). No prior research has been done using the Zebris FDM-system to analyze changes in gait after ankle adjustment. Method: Sixty participants between the age of 15 and 45 years were recruited. The participants were asked to sign a consent form after which a thorough case history, full physical exam and foot and ankle regional examination were performed. Participants were included in the study if they were of the correct age, had a chronic history of minor ankle sprain and had palpable motion restrictions of ankle joint range of motion. Participants were excluded if they had a history of severe ankle injury or ankle surgery, had any contraindications to chiropractic adjustment or were currently undergoing any other treatment that could interfere with the study, including the use of certain medications. Each participant underwent a gait assessment before and after they received a chiropractic adjustment to the restricted ankle joint. Procedure: Objective measurements were obtained using the Zebris FDM-system before and after participants received one chiropractic adjustment using a long axis distraction technique. The Zebris FDM-system uses capacitive force sensors arranged on a platform in a high density. The measuring plate allows dynamic force distribution to be analysed during gait. The length of the Zebris platform allowed successive footfalls to be captured and measurements taken during three full gait cycles were used in the analysis. All data was processed using the WinFDM program to produce a gait report (Zebris Medical GmbH, 2008) Results: A statistically significant change was seen in the single support line on the non-adjusted side. Changes were measured in the other gait parameters although they were not statistically significant. Conclusion: This study has shown that chiropractic adjustment of the ankle joint has an effect on the path of centre of pressure and foot rotation during gait. It also helps clinicians to see that the adjustment has a bilateral effect. Future studies will be able to determine whether this is a positive or a negative outcome as the limits of normal and pathological gait using these parameters have not yet been set. Chiropractors can treat patients with a history of chronic ankle sprain more effectively if they have a better understanding of residual motion restrictions and movement patterns after acute ankle sprain. A future study including several treatments could be beneficial as clinical chiropractic practice would most likely involve more than one treatment of a patient with a history of ankle sprain. In this way the lasting and accumulative effects of chiropractic adjustment could be measured.

Purpose of study: Examine ASO (soft) and Malleoloc semi-rigid stirrup (SRS) ankle orthosis designs on ankle kinematics during field-sport movements: sprint, one-legged jump, and 45-degree cut. Participants: 13 competitive Ultimate players who regularly wore an ankle orthosis during physical activity. Methods: ASO or Malleoloc orthosis was randomly assigned to each person. Kinematic data were captured while the participants performed several trials for each movement in a motion analysis laboratory. Participants repeated the protocol with the other orthosis. Results: ASO allowed significantly more plantar-flexion during weight acceptance of the planting foot in cutting (p=0.038). In jumping, the Malleoloc allowed significantly more eversion-inversion range during stance (p=0.048) and eversion-inversion angular velocity from midstance to toe-off (p=0.026). Qualitative data also showed a significant preference for ASO. Conclusion: Hypotheses that ankle inversion and eversion would be greater with the ASO; and plantar-flexion and dorsiflexion would be greater with the Malleoloc were refuted.

The purpose of this study is to determine the effect of short-time cold pack cryotherapy in thermoreceptors, therefore, proprioception via deep sensation receptors and sense of balance on ankle joint in healthy adults. In the subject, I refer to other studies using the word proprioception when measuring the cold effect in the balance of the ankle joint. Mainly, cold therapy is affecting to the thermoreceptors but there might be input also to change neuromuscular transmission. The aim of the experimental process is to identify if the cold application on the ankle joint for 20 minutes is decreasing dynamic postural stability and the sense of balance in laboratory environment. Short term cryotherapy effect is measured within 12 participants divided into two groups: control and study group. Both groups went through the first measurement, 20 minutes rest with or without cold application and second measurement directly after the rest period. The dynamic posturography machine SMART Balance Master System (NeuroCom) was used to evaluate somatosensory outcome in the experiment. In the systematic review the previous studies are investigated within same settings as on experimental process, short time cold application on ankle joint measuring the effect on ankle proprioception and joint position sense. The...

Dynamic standing balance is essential to perform functional activities and is included in the treatment of many lower extremity injuries. Physiotherapists utilize many methods to restore standing balance including stability exercises, functional retraining, and manual therapy. The purpose of this study was to investigate the effects of a rearfoot distraction manipulation on dynamic standing balance. Twenty healthy participants (age: 24.4 ± 2.8 years; height: 162.9 ± 37.7 cm; mass: 68.0 ± 4.8 kg; right leg dominant = 20) completed this study. Following familiarization, dynamic standing balance was assessed during: (1) an experimental condition immediately following a rearfoot distraction manipulation, and (2) a control condition. Dominant leg balance was quantified using the Y-balance test which measures lower extremity reach distances. Reach distances were normalized to leg length and measured in the anterior, posteromedial and posterolateral directions. Overall balance was calculated through the summing of all normalized directions. Paired t-tests and Wilcoxon rank tests were used to compare balance scores for parametric and non-parametric data as appropriate. Significance was set at 0.05 a priori. Effect size (ES) was calculated to determine the clinical impact of the manipulation. Increased reach distances (indicating improved balance) were noted following manipulation for overall balance (p = 0.03, ES = 0.26) and in the posteromedial direction (p = 0.01, ES = 0.42). Reach distances did not differ for the anterior (p = 0.11, ES = 0.16) or posterolateral (p = 0.11, ES = 0.25) components. Dynamic standing balance improved after a rearfoot distraction manipulation in healthy participants. It is hypothesized that manual therapy applied to the foot and ankle may be beneficial to augment other therapeutic modalities when working with patients to improve dynamic standing balance.

It was questioned whether a unilateral stretching program would induce a crosstraining effect in the contralateral muscle. To test this, 13 untrained individuals participated in a 10-week stretching program while 12 other untrained individuals served as a control group. For the experimental group, the right calf muscle was stretched 4 times for 30 seconds, with a 30-second rest between stretches, 3 d·wk -1 for 10 weeks. Strength determined via 1 repetition maximum (1RM) unilateral standing toe raise, and range of motion (ROM) were measured pre-post. In the treatment group, the stretched calf muscle had a significant (p < 0.05) 8% increase in ROM, whereas the nonstretched calf muscle had a significant 1% decrease in ROM. The 1 RM of the stretched calf muscle significantly increased 29%, whereas the 1RM of the nonstretched calf muscle significantly increased 11%. In the control group, neither 1RM nor ROM changed for either leg. The results indicate that 10 weeks of stretching only the right calf will significantly increase the strength of both calves. Hence, chronic stretching can also induce a crosstraining effect for strength but not for the ROM. This study also validates earlier findings suggesting that stretching can elicit strength gains in untrained individuals.

<p>Our healthcare system is experiencing a substantial economic burden, and one of the contributing factors is ankle injury - particularly ankle sprains - and the resulting chronic conditions like ankle instability and osteoarthritis. Ankle sprains commonly occur in sports such as basketball, where sudden, lateral changes in direction are common. As a shoe provides the foundational support for an athlete, a simple slipping/tipping analysis was performed to derive a stability criterion that relates impact forces and shoe geometry. The criterion was populated with geometric measurements from seven currently-available basketball shoes and impact forces seen in lateral maneuvers from several published studies to generate multiple cases to observe if the shoes were safe. Of the 35 cases (seven different shoes applied in six different loading conditions) there were six cases where the shoe passed the stability criterion and was considered safe. Given that the impact forces in lateral movements likely will not change, the geometry of the shoes should be considered to reduce the chance of tipping of the shoe (i.e. rolling of the ankle) and risk of injury to the athlete.</p><p>Another contributing factor to the healthcare system's economic burden is limb loss, and the negative effects of ill-fitting and ill-functioning prosthetic devices. Examples of these secondary complications are osteoarthritis and tissue breakdown, which are thought to result from uneven joint loading and asymmetric gait. In light of this, a prosthetic ankle was developed that employs a three degree of freedom system modeled with a ball-in-socket joint. The range of motion of this joint can be custom-bounded by the system of nubs and cavities, along with shims that can be inserted around the joint shaft, to control dorsiflexion, plantarflexion, inversion, eversion, and medial/lateral rotation in the transverse plane. A joint like this, which enables the user to have a more natural gait, will help reduce the onset of conditions like osteoarthritis, ultimately reducing the demand on resources from the healthcare system.</p><p>Another effort to mitigate the burden on the healthcare system is seen through the development of a wearable resistance device that is designed to help prevent injury by strengthening musculoskeletal and neuromuscular systems during sport-specific movements. While traditional gym training is beneficial for an athlete's overall health and fitness, it tends to lack in adequately preparing the athlete for sport-specific movements. Thus, a wearable resistance system is beneficial in that it can provide resistance training during sport to enhance and strengthen an athlete's neuromuscular and musculoskeletal systems. In this study, five recreational runners performed running trials on an instrumented treadmill with and without the wearable resistance system. Force plate and surface electromyography (sEMG) data were collected to observe changes in the muscle activation in both legs. Additionally, sEMG data was examined to detect any effect on left/right symmetry in each subject. </p><p>These studies can all be enhanced with the incorporation of a newly-developed skeletal muscle force model that provides more accurate estimates of individualized muscle forces to better predict surrounding musculoskeletal tissue and joint contact loading. It is founded in dimensional analysis and uses electromyography and the muscle force-length, force-velocity, and force-frequency curves as inputs. The constitutive equation gives way to a unique application of inverse-dynamics that avoids the issue of indeterminacy when reaction moments and ligament loading are minimized in a joint. The ankle joint is used as an example for developing the equations that culminate into a system of linear equations. Seventeen subjects (8 males, 9 females) performed five different exercises geared towards activating the primary muscles crossing the ankle joint. The moments about the ankle joint due to the calculated muscle forces were compared to the sum of the moments due to all other sources and the kinematic terms in the second Newton-Euler equation of rigid body motion. Average percent errors for the \(\vec{B}\) components for each subject ranged from 4.2\% to 15.5\% with a total average percent error across all subjects of 8.2\%. Not only is this muscle force model physiologically relevant, but it can be calibrated and used to predict joint contact loading and loading in the surrounding tissues. Thus, it will be beneficial for use in designing biomechanics equipment for athletes like basketball players, or in designing prosthetic devices that function more like a natural joint. Furthermore, this model can be used in conjunction with the wearable resistance device to validate it's effects on the strengthening of neuromuscular and musculoskeletal systems over time.</p>

Eight functionally identified group Ia muscle afferents from triceps surae or plantaris muscles were labeled intraaxonally with horseradish peroxidase (HRP) in seven adult cats. Subsequently, HRP was injected into two to six homonymous or heteronymous alpha-motoneurons per animal (total = 22), each identified by motor unit type and located near the site of afferent injection. The complete trajectories of labeled afferents were reconstructed, and putative synaptic contacts on HRP-labeled motoneurons were identified at high magnification. Dendritic paths from each contact were also mapped and measured. A total of 24 contact systems (the combination of a group Ia afferent and a postsynaptic motoneuron) were reconstructed, of which 17 were homonymous, and seven were heteronymous. Overall, homonymous contact systems had an average of 9.6 boutons, whereas heteronymous contact systems had an average of 5.9 boutons. The average number of boutons found on type S motoneurons in homonymous contact systems was smaller (6.4, range 3-17) than in systems involving types FF or FR motoneurons (FF: 10.4, range 4-18; FR: 11.3, range 4-32). Neither of these differences were statistically significant. In contrast to earlier reports, a majority (15/24) of contact systems included more than one collateral from the same Ia afferent. The complexity (number of branch points) in the arborization pathway leading to each contact (overall mean 8.4 +/- 3.3) was virtually identical in all contact systems, irrespective of the type of postsynaptic motoneuron. The three-dimensional distribution of group Ia contacts was not coextensive with the radially organized dendrites of motoneurons: Dendrites oriented in the ventromedial to dorsolateral axis had the fewest (8%) contacts, whereas rostrocaudal dendrites had the most (63%) contacts. Nevertheless, contacts were widely distributed on the motoneuron surface, with few on and near the soma (< or = 200 microns radial distance from the soma) or on the most distal parts of the tree (> or = 1,000 microns). The boutons in individual contact systems also showed wide spatial and estimated electrotonic distributions; only 3/24 systems had all contact located within a restricted spatial/electrotonic region. The relations between these anatomical results and existing electrophysiological data on group Ia synaptic potentials are discussed.

Some have suggested acute increases in musculotendinous stiffness (k) following whole body vibration (WBV). Others propose that chronic ankle instability (CAI) may alter k of the lower extremity. Changes in proprioceptive activity and/or gamma motoneuron activation post-WBV and/or due to CAI could lead to alterations in k. However, little is known about acute effects of WBV on k and less is known about changes in k with CAI. PURPOSE: Assess differences in vertical and joint k between healthy and CAI subjects during single-limb landings and detect alterations in k measures post-vibration. METHODS: Subjects were identified as CAI via the FAAM, MAII and special testing. Thirty-five CAI subjects (17 males, 18 females; age = 22 ± 7 yr; height = 1.73 ± 0.23 m; mass = 70 ± 30 kg) and 35 matched healthy subjects (17 males, 18 females; age = 23 ± 5 yr; height = 1.73 ± 0.21 m; mass = 70 ± 35 kg) qualified for this study. Kinetic (2000 Hz) and kinematic (250 Hz) data were recorded during several jump landings pre- and post-WBV. Five repetitions of WBV, at 26 Hz and 4 mm amplitude, were introduced between pre- and post-WBV jump trials. The jump task included a double-limb jump followed by a single-limb landing and a subsequent contralateral hop. Vertical k (∆vertical GRF/center of mass vertical displacement), hip, knee and ankle joint k (∆joint moment/∆joint angle) were calculated, averaged across five successful pre-WBV and across six post-WBV trials. An ANOVA was used to detect between-group differences, while an ANCOVA was used to analyze within-group differences post-WBV using pre-measures as covariates. A pseudo-Bonferroni adjustment was performed prior to statistical analysis (p < 0.01). RESULTS: No between-group differences were observed for any of the variables (F1,68 = 0.020 to 1.400, p = 0.240 to 0.890). A significant increase in vertical k was observed post-WBV for the healthy group (t67 = 2.760, p = 0.008), but not for the CAI group (t67 = 0.370, p = 0.720). The CAI group did demonstrate a decrease in ankle (t67 = -3.130, p = 0.003) and knee (t67 = -3.490, p = 0.001) joint k post-vibration. No other within-group differences were observed post-WBV (p > 0.01). CONCLUSIONS: It appears that WBV does acutely increase vertical k in healthy subjects. However, this treatment effect was not observed in CAI. Further research is needed to assess how k is regulated in CAI subjects and why CAI subjects responded differently to WBV.

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