Patellofemoral Joint Loading during the Performance of the Wall Squat and Ball Squat with Heel-to-Wall-Distance Variations.

Introduction: Although bodyweight wall and ball squats are commonly used during patellofemoral rehabilitation, patellofemoral loading while performing these exercises is unknown, which makes it difficult for clinicians to know how to use these exercises in progressing a patient with patellofemoral pathology. Therefore, the purpose was to quantify patellofemoral force and stress between two bodyweight squat variations (ball squat vs wall squat) and between two heel-to-wall-distance (HTWD) variations (long HTWD vs short HTWD).

Methods: Sixteen participants performed a dynamic ball squat and wall squat with long HTWD and short HTWD.

Patient Experience and Perceived Benefits of Physical Therapy after Lower Limb Amputation in Middle-Aged and Older Adults.

The current study aimed to investigate the long-term effects of receiving post-amputation physical therapy (PT) on individuals' self-reported functional outcomes and quality of life in middle-aged to older adults with lower limb amputation (LLA). Further, we qualitatively explored the patients' perception and experience of PT post-amputation. We assessed participants' functional outcomes using Short-Form Health Survey, Prosthetic Evaluation Questionnaire-Physical Mobility portion, and Fear of Falling Avoidance Behavior Questionnaire.

Patellofemoral Joint Loading in Forward Lunge With Step Length and Height Variations.

The objective was to assess how patellofemoral loads (joint force and stress) change while lunging with step length and step height variations. Sixteen participants performed a forward lunge using short and long steps at ground level and up to a 10-cm platform. Electromyography, ground reaction force, and 3D motion were captured, and patellofemoral loads were calculated as a function of knee angle.

Kinematic and Radiographic Evaluation of Acromioclavicular Reconstruction with a Synthetic Ligament.

Purpose: The optimal surgical technique for unstable acromioclavicular (AC) and coracoclavicular (CC) joint injuries has not yet been established. The biomechanical and radiographic effect of the LockDown device, a synthetic ligament for AC joint reconstruction, was evaluated to assess the optimal surgical technique for unstable AC and CC joint injuries. It was hypothesized that the LockDown device would restore AC joint kinematics and radiographic stability to near native values.

Patellofemoral Joint Loading During the Performance of the Forward and Side Lunge with Step Height Variations.

Background: Forward and side lunge exercises strengthen hip and thigh musculature, enhance patellofemoral joint stability, and are commonly used during patellofemoral rehabilitation and training for sport.

Hypothesis/purpose: The purpose was to quantify, via calculated estimates, patellofemoral force and stress between two lunge type variations (forward lunge versus side lunge) and between two step height variations (ground level versus 10 cm platform). The hypotheses were that patellofemoral force and stress would be greater at all knee angles performing the bodyweight side lunge compared to the bodyweight forward lunge, and greater when performing the forward and side lunge at ground level compared to up a 10cm platform.

Amputation Rehabilitation and Prosthetics Curricula in Physical Therapist Professional Education Programs.

Introduction: Curricular guidelines do not exist currently for content related to amputation rehabilitation and prosthetics in entry-level physical therapy education programs. Documents exist to provide context, but before guidelines can be written, the current content of entry-level physical therapist professional education programs must be known.

Methods: Faculty members teaching amputation rehabilitation and prosthetics at 225 accredited physical therapist education programs in the United States were recruited via e-mail.

Kinetic and Kinematic Assessment of an Individual Post-Stroke with Stiff-Knee Gait Using Various Orthotic Devices: A Case Study.

It is important for individuals who have suffered a stroke to be able to experience a weight-bearing aerobic workout, if able. For individuals post-stroke who experience genu recurvatum during gait, care should be taken to minimize abnormal forces on the posterior and internal structures of the involved knee. The purpose of this case study was to assess the biomechanics of the involved knee during the stance phase of gait of an individual who, post-stroke, walked with a stiff-knee gait in 9 different orthotic conditions.

Higher Knee Flexion Moment During the Second Half of the Stance Phase of Gait Is Associated With the Progression of Osteoarthritis of the Patellofemoral Joint on Magnetic Resonance Imaging.

Study Design: Controlled laboratory study, longitudinal design.

Objective: To examine whether baseline knee flexion moment or impulse during walking is associated with the progression of osteoarthritis (OA) with magnetic resonance imaging of the patellofemoral joint (PFJ) at 1 year.

Background: Patellofemoral joint OA is highly prevalent and a major source of pain and dysfunction.

Individuals with isolated patellofemoral joint osteoarthritis exhibit higher mechanical loading at the knee during the second half of the stance phase.

Background: Patellofemoral joint osteoarthritis is a highly prevalent disease and an important source of pain and disability. Nonetheless, biomechanical risk factors associated with this disease remain unclear. The purpose of this study was to compare biomechanical factors that are associated with patellofemoral joint loading during walking between individuals with isolated patellofemoral joint osteoarthritis and no osteoarthritis.

Are There Sex Differences in Knee Cartilage Composition and Walking Mechanics in Healthy and Osteoarthritis Populations?

Background: Women are at a greater risk for knee osteoarthritis (OA), but reasons for this greater risk in women are not well understood. It may be possible that differences in cartilage composition and walking mechanics are related to greater OA risk in women.

Questions/purposes: (1) Do women have higher knee cartilage and meniscus T1ρ than men in young healthy, middle-aged non-OA and OA populations? (2) Do women exhibit greater static and dynamic (during walking) knee loading than men in young healthy, middle-aged non-OA and OA populations?

Methods: Data were collected from three cohorts: (1) young active (<35 years) (20 men, 13 women); (2) middle-aged (≥35 years) without OA (Kellgren-Lawrence [KL] grade < 2) (43 men, 65 women); and (3) middle-aged with OA (KL>1) (18 men, 25 women).

Biomechanical performance of baseball pitchers with a history of ulnar collateral ligament reconstruction.

Background: A relatively high number of active professional baseball pitchers have a history of ulnar collateral ligament reconstruction (UCLr) on their throwing elbow. Controversy exists in the literature about whether professional baseball pitchers regain optimal performance after return from UCLr. It has been suggested that pitchers may have different biomechanics after UCLr, but this has not been previously tested.

Magnetic resonance analysis of loaded meniscus deformation: a novel technique comparing participants with and without radiographic knee osteoarthritis.

Objective: To establish a novel method of quantifying meniscal deformation using loaded MRI. More specifically, the goals were to evaluate the (1) accuracy, (2) inter-rater reliability, (3) intra-rater reliability, and (4) scan-rescan reliability. The secondary purpose of this experiment was to evaluate group differences in meniscal deformation in participants with and without radiographic knee OA.

Differences in neuromuscular control and quadriceps morphology between potential copers and noncopers following anterior cruciate ligament injury.

Study Design: Prospective cross-sectional study.

Objectives: To compare knee muscle morphology and voluntary neuromuscular control in individuals who sustained an anterior cruciate ligament (ACL) injury and were identified as being capable of avoiding surgery (potential copers) and those who were recommended for surgery (noncopers), within 6 months of injury.

Background: Quadriceps atrophy and poor neuromuscular control have been found in noncopers.

Changes in the preferred transition speed with added mass to the foot.

This study was conducted to investigate whether adding mass to subjects' feet affects the preferred transition speed (PTS), and to ascertain whether selected swing phase variables (maximum ankle dorsiflexion angular velocity, angular acceleration, joint moment, and joint power) are determinants of the PTS, based upon four previously established criteria. After the PTS of 24 healthy active male subjects was found, using an incremental protocol in loaded (2 kg mass added to each shoe) and unloaded (shoes only) conditions, subjects walked at three speeds (60%, 80%, and 100% of PTS) and ran at one speed (100% of PTS) on a motor-driven treadmill while relevant data were collected. The PTS of the unloaded condition (2.

Characteristics of human knee muscle coordination during isometric contractions in a standing posture: the effect of limb task.

Different functional roles for the hands have been demonstrated, however leg control is not as well understood. The purpose of the present study was to evaluate bilateral knee neuromuscular control to determine if the limb receiving greater attention would have more well-tuned control compared to an unattended limb. Surface electrodes were placed on seven muscles of each limb, before standing on two force platforms.

Early regeneration determines long-term graft site morphology and function after reconstruction of the anterior cruciate ligament with semitendinosus-gracilis autograft: a case series.

Purpose/background: The semitendinosus-gracilis tendon autograft is often used to reconstruct the anterior cruciate ligament. Tendon regeneration appears to occur for most individuals in the short term, but little is known about the long-term effects of graft harvest. The purpose of this study was to describe the effect of semitendinosis-gracilis tendon graft harvest on muscle and tendon morphology at least five years following reconstruction in a case series.

Cruciate ligament loading during common knee rehabilitation exercises.

Cruciate ligament injuries are common and may lead to dysfunction if not rehabilitated. Understanding how to progress anterior cruciate ligament and posterior cruciate ligament loading, early after injury or reconstruction, helps clinicians prescribe rehabilitation exercises in a safe manner to enhance recovery. Commonly prescribed therapeutic exercises include both weight-bearing exercise and non-weight-bearing exercise.

Anterior cruciate ligament strain and tensile forces for weight-bearing and non-weight-bearing exercises: a guide to exercise selection.

There is a growing body of evidence documenting loads applied to the anterior cruciate ligament (ACL) for weight-bearing and non-weight-bearing exercises. ACL loading has been quantified by inverse dynamics techniques that measure anterior shear force at the tibiofemoral joint (net force primarily restrained by the ACL), ACL strain (defined as change in ACL length with respect to original length and expressed as a percentage) measured directly in vivo, and ACL tensile force estimated through mathematical modeling and computer optimization techniques. A review of the biomechanical literature indicates the following: ACL loading is generally greater with non-weight-bearing compared to weight-bearing exercises; with both types of exercises, the ACL is loaded to a greater extent between 10° to 50° of knee flexion (generally peaking between 10° and 30°) compared to 50° to 100° of knee flexion; and loads on the ACL change according to exercise technique (such as trunk position).

Effects of statins on skeletal muscle: a perspective for physical therapists.

Hyperlipidemia, also known as high blood cholesterol, is a cardiovascular health risk that affects more than one third of adults in the United States. Statins are commonly prescribed and successful lipid-lowering medications that reduce the risks associated with cardiovascular disease. The side effects most commonly associated with statin use involve muscle cramping, soreness, fatigue, weakness, and, in rare cases, rapid muscle breakdown that can lead to death.

Estimation of ligament loading and anterior tibial translation in healthy and ACL-deficient knees during gait and the influence of increasing tibial slope using EMG-driven approach.

The purpose of this study was to develop a biomechanical model to estimate anterior tibial translation (ATT), anterior shear forces, and ligament loading in the healthy and anterior cruciate ligament (ACL)-deficient knee joint during gait. This model used electromyography (EMG), joint position, and force plate data as inputs to calculate ligament loading during stance phase. First, an EMG-driven model was used to calculate forces for the major muscles crossing the knee joint.

Cruciate ligament forces between short-step and long-step forward lunge.

Purpose: The purpose of this study was to compare cruciate ligament forces between the forward lunge with a short step (forward lunge short) and the forward lunge with a long step (forward lunge long).

Methods: Eighteen subjects used their 12-repetition maximum weight while performing the forward lunge short and long with and without a stride. EMG, force, and kinematic variables were input into a biomechanical model using optimization, and cruciate ligament forces were calculated as a function of knee angle.

Cruciate ligament tensile forces during the forward and side lunge.

Background: Although weight bearing lunge exercises are frequently employed during anterior cruciate ligament and posterior cruciate ligament rehabilitation, cruciate ligament tensile forces are currently unknown while performing forward and side lunge exercises with and without a stride.

Methods: Eighteen subjects used their 12 repetition maximum weight while performing a forward lunge and side lunge with and without a stride. A motion analysis system and biomechanical model were used to estimate cruciate ligament forces during lunging as a function of 0-90 degrees knee angles.

Patellofemoral joint force and stress during the wall squat and one-leg squat.

Purpose: To compare patellofemoral compressive force and stress during the one-leg squat and two variations of the wall squat.

Methods: Eighteen subjects used their 12 repetition maximum (12 RM) weight while performing the wall squat with the feet closer to the wall (wall squat short), the wall squat with the feet farther away from the wall (wall squat long), and the one-leg squat. EMG, force platform, and kinematic variables were input into a biomechanical model to calculate patellofemoral compressive force and stress as a function of knee angle.

Cruciate ligament force during the wall squat and the one-leg squat.

Purpose: To compare cruciate ligament forces during wall squat and one-leg squat exercises.

Methods: Eighteen subjects performed the wall squat with feet closer to the wall (wall squat short), the wall squat with feet farther from the wall (wall squat long), and the one-leg squat. EMG, force, and kinematic variables were input into a biomechanical model using optimization.