The Effects of Anticipation on the Mechanics of the Knee During Single-Leg Cutting Tasks: A Systematic Review.
Authors: Almonroeder TG, Garcia G, Kurt M
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ACL injuries are common in sports, which has resulted in the development of risk screening and injury prevention programs to target modifiable neuromuscular risk factors. Previous studies that have analyzed single-leg cutting tasks have reported that the anticipation status of the task (pre-planned vs. unanticipated) has a significant effect on the mechanics of the knee. The purpose of this systematic review was to assess the effect of anticipation on the mechanics of the knee in the sagittal, frontal, and transverse planes during tasks that athletes frequently perform during competition. The authors identified 13 studies that met the criteria for inclusion in this systematic review. From the review it appears that tasks which do not allow a subject to pre-plan their movement strategy promote knee mechanics which may increase an athlete’s risk of injury. The authors suggest that those involved in the development and implementation of ACL injury risk screening and prevention programs may want to consider incorporating tasks that do not allow time for pre-planning. These unanticipated tasks may more closely mimic the demands of the sports environment and may promote mechanics which increase the risk of injury.
Clinical Prognostic Factors For Patients With Anterior Knee Pain In Physical Therapy; A Systematic Review.
Authors: Panken AM, Heymans MW, vOort L, Verhagen AP
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Although many authors have studied the prognostic factors that may contribute to anterior knee pain, synthesis of the existing evidence has not been performed. The purpose of this systematic review was to summarize and examine existing prognostic models for patients with anterior knee pain that first present to physical therapists (primary care setting). For this review Pubmed, Embase and Cinahl databases were searched and published papers that reported prognostic models for patients with anterior knee pain that first present to physical therapists (primary care setting) were selected. Nine studies were included. The quality scores of these studies ranged from 9 to 17 positive items out of 21 items included in the assessment for quality. None of the prognostic models were validated internally or externally. Four studies were considered to be of sufficient quality. The authors of these four studies found 14 different predictors significantly related to pain intensity of which seven had limited evidence. Fifteen different predictors were found that were related to function of which seven had limited evidence. Furthermore, strong evidence was found that baseline pain intensity, pain coping and kinesiophobia were of no predictive value for pain, and activity related pain, and that pain coping and kinesiophobia were of no predictive value for function at follow up. Because of the low quality of a number of studies and the heterogeneity of the examined variables and outcome measures of most of the studies, only limited evidence for seven predictors related to pain and seven predictors related to function in patients with anterior knee pain in a primary care setting was found.
Effect of Restricted Hip Flexor Muscle Length on Hip Extensor Muscle Activity and Lower Extremity Biomechanics in College-Aged Female Soccer Players.
Authors: Mills M, Frank B, Goto S, Blackburn T, Cates S, Clark M, Aguilar A, Fava N, Padua D
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Hip flexor tightness is theorized to alter antagonist muscle function through reciprocal inhibition and synergistic dominance mechanisms. Synergistic dominance may result in altered movement patterns and increased risk of lower extremity injury. Subjects with and without clinically restricted hip flexor muscle length were assessed in order to compare hip extensor muscle activation, internal hip and knee extension moments during double-leg squatting, and gluteus maximus strength. Using a modified Thomas Test, female soccer athletes were assigned to a restricted (>0° of sagittal plane hip motion above the horizontal) or normal (>15° of sagittal plane hip motion below horizontal) hip flexor muscle length groups. Surface electromyographic (sEMG) activity of the gluteus maximus and biceps femoris, and net internal hip and knee extension moments were measured between groups during a double-leg squat. Isometric gluteus maximus strength was assessed using handheld dynamometry. The authors found that in individuals with restricted hip flexor muscle length demonstrated less gluteus maximus activation (p=0.008) and a lower gluteus maximus:biceps femoris co-activation ratio (p=0.004). There were no significant differences (p>0.05) in hip or knee extension moments, isometric gluteus maximus strength, or biceps femoris activation between groups. The authors concluded that female soccer athletes with hip flexor muscle tightness exhibit less gluteus maximus activation and lower gluteus maximus:biceps femoris co-activation while producing similar net hip and knee extension moments. Thus, individuals with hip flexor muscle tightness appear to utilize different neuromuscular strategies to control lower extremity motion.
Relationship Between the Y-Balance Test scores and Soft Tissue Injury Incidence in a Soccer Team.
Authors: Gonell AC, Romero JAP, Soler MA
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Although the dynamic balance has been proposed as a risk factor for sports-related injuries, few researchers have used the Y-balance test to examine this relationship. The purpose of this study was to determine if the Y-Balance Test (YBT) is a valid test for determining subjects susceptible to soft tissue injury among soccer players on a professional team. Prior to the 2011 football (soccer) season, the anterior, posteromedial and posterolateral YBT reach distances and limb lengths of 74 soccer players were measured. Athletes’ physiotherapists documented how many days the players were unable to play due to the injuries. After normalizing for lower limb length, each of the reach distances, right/left reach distance difference and composite reach distance were examined using odds ratios and logistic regression analysis. Logistic regression models indicated that players with a difference of equal or greater than 4cm between lower limbs in posteromedial direction were 3.86 more likely to sustain a lower extremity injury (p=0.001). Results indicated that players who had lower scores than the mean in each reach direction, independently, were almost two times more likely to sustain an injury. The results suggest that YBT can be incorporated into physical examinations to identify soccer players who are susceptible to risk of injury.
Changes in Patellofemoral Joint Stress During Running with the Application of a Prefabricated Foot Orthotic.
Authors: Almonroeder TG, Benson LC, O’Connor KM
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Foot orthotics are commonly utilized in the treatment of patellofemoral pain (PFP) and have shown clinical benefit; however, their mechanism of action remains unclear. Patellofemoral joint stress (PFJS) is thought to be one of the main etiological factors associated with PFP. The primary purpose of this study was to investigate the effects of a prefabricated foot orthotic with 5° of medial rearfoot wedging on the magnitude and the timing of the peak PFJS in a group of healthy female recreational athletes. The hypothesis was that there would be significant reduction in the peak patellofemoral joint stress and a delay in the timing of this peak in the orthotic condition. Kinematic and kinetic data were collected during running trials in a group of healthy, female recreational athletes. The knee angle and moment data in the sagittal plane were incorporated into a previously developed model to estimate patellofemoral joint stress. The dependent variables of interest were the peak PFJS as well as the percentage of stance at which this peak occurred, as both the magnitude and the timing of the joint loading are thought to be important in overuse running injuries. The peak patellofemoral joint stress significantly increased in the orthotic condition by 5.8% (p=.02, ES=0.24), which does not support the initial hypothesis. However, the orthotic did significantly delay the timing of the peak during the stance phase by 3.8% (p=.002, ES=0.47). The finding that the peak patellofemoral joint stress increased in the orthotic condition did not support the initial hypothesis. However, the finding that the timing of this peak was delayed to later in the stance phase in the orthotic condition did support the initial hypothesis and may be related to the clinical improvements previously reported in subjects with PFP.
Reliability of Two Methods of Clinical Examination of the Flexibility of the Hip Adductor Muscles.
Authors: Cejudo A, Ayala F, De Baranda PS, Santonja F
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An inadequate level of flexibility of the adductor muscles is one of the most critical risk factors for chronic groin pain and strains. However, measurement methods of adductor muscle flexibility are not well defined. The purpose of this study was to determine the inter-session reliability of the measures of biarticular and monoarticular adductor muscle flexibility obtained using two tests: passive hip abduction with the knee flexed over the edge of the plinth test (PHA) and passive hip abduction test at 90º of hip flexion (PHA90º). Fifty healthy recreational athletes participated in this study. All participants performed the PHA and PHA90º on four different occasions, with a two-week interval between testing sessions. Reliability was examined through the change in the mean between consecutive pairs of testing sessions (ChM), standard error of measurement expressed in absolute values (SEM) and as a percentage of the mean score (%SEM), minimal detectable change at 95% confidence interval (MDC95), and intraclass correlation coefficients (ICC2,k). The findings showed negligible or trivial ChM values for the two adductor flexibility measures analyzed (<2º). Furthermore, the SEM and MDC95 were 2.1º and 5.9º and 2.2º and 6.2º for the measures obtained from the PHA and PHA90º, respectively, with %SEM scores lower than 5% and ICC scores higher than 0.90. The findings from this study suggest that the adductor muscle flexibility measures analyzed have good to excellent inter-session reliability in recreational athletes. Thus, clinicians can be 95% confident that an observed change between two measures larger than 5.9º and 6.2º for the flexibility measures obtained from the PHA and PHA90º, respectively, would indicate a real change in muscle flexibility.
Temporal pattern of kinesiology tape efficacy on hamstring extensibility.
Authors: Farquharson C, Greig M
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Kinesiology tape (KT) has been advocated as a means of improving muscle flexibility, a potential modifiable risk factor for injury. The epidemiology and etiology of hamstring injuries in sport have been well documented. The purpose of this study was to compare the temporal pattern of efficacy of KT and traditional stretching techniques on hamstring extensibility over a five day period. Thirty recreationally active male participants (Mean ± SD: age 20.0 ± 1.55 years; height 179.3 ± 4.94 cm; mass 76.9 ± 7.57 kg) completed an active knee extension assessment (of the dominant leg) as a measure of hamstring extensibility. Three experimental interventions were applied in randomized order: Kinesiology tape (KT), static stretch (SS), proprioceptive neuromuscular facilitation (PNF). Measures were taken at baseline, +1min, +30mins, +3days and +5days days after each intervention. The temporal pattern of change in active knee extension was modelled as a range of regression polynomials for each intervention, quantified as the regression coefficient. The results demonstrated that hamstring ROM with KT application at +3days was significantly greater than baseline (129.18 ± 15.46%, p = 0.01), SS (106.99 ± 9.84%, p = 0.03) and PNF (107.42 ± 136.13%, p = 0.03) interventions. The temporal pattern of changes in ROM for SS and PNF were best modelled by a negative linear function, although the strength of the correlation was weak in each case. In contrast, the KT data was optimised using a quadratic polynomial function (r2 = 0.60), which yielded an optimum time of 2.76 days, eliciting a predicted ROM of 129.6% relative to baseline. The authors concluded that each intervention displayed a unique temporal pattern of changes in active knee extension. SS was best suited to immediate improvements, and PNF to +30 minutes in hamstring extensibility, whereas kinesiology tape offered advantages over a longer duration, peaking at 2.76 days. These findings have implications for the choice of intervention, timing and duration to assist clinicians in both a sporting and clinical context.
Pre-operative Low Back Pain Negatively Affects Self-Reported Function in Individuals Undergoing Hip Arthroscopy.
Authors: Becker LC, Carter-Kelley S, Ellis T, Cenkus K, Di Stasi SL
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Low back pain (LBP) is a common source of disability in adults and highly prevalent in patients with painful hip pathology. Persistent LBP after hip arthroplasty is associated with lower self-reported function, however, the effect of pre-operative LBP in patients undergoing hip arthroscopy for femoroacetabular impingement (FAI) has not been evaluated. The purpose of this study was to determine whether improvements in self-reported hip function following arthroscopic surgery for FAI differed between those with and without reports of pre-operative low back pain. Three hundred eighteen subjects undergoing primary hip arthroscopy for clinically and radiographically-confirmed FAI were recruited and consented. One hundred fifty-six of these subjects completed the International Hip Outcomes Tool (iHOT-33) and the Hip Outcome Score Activities of Daily Living Subscale (HOS-ADL) before, and six and 12 months after surgery. Subjects were grouped based on the self-reported presence or absence of LBP prior to arthroscopy. A repeated measures analysis of variance was used to determine the effects of time and low back pain on iHOT-33 and HOS-ADL scores. Seventy-five of 156 subjects (48.1%) reported LBP prior to surgery. A main effect of time was found for both outcome measures (p<0.001), demonstrating improvement in self-reported outcomes over the testing period. There was a main effect of group for the iHOT-33 (LBP: 52.0 [47.9,56.0]; no LBP 57.9 [53.9,61.8]; p = 0.043) but not for the HOS-ADL (LBP: 75.2 [72.2,78.2]; no LBP 78.8 [75.9,81.7]; p = 0.088) indicating that subjects with pre-operative LBP had poorer self-reported function per the iHOT-33 compared to those without LBP. The authors concluded that self-reported hip function scores improved regardless of the presence of pre-operative LBP; however subjects with LBP reported poorer self-reported function per the iHOT-33 as compared to those without LBP up to 12 months post-operatively.
Immediate Effects of a Dynamic Rotation-Specific Warm-Up on X-Factor and X-Factor Stretch in the Amateur Golfer.
Authors: Henry E, Berglund K, Millar L, Locke F
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Recent evidence suggests that performing a warm-up prior to golf can improve performance and reduce injuries. While some characteristics of effective golf warm-ups have been determined, no studies have explored a rotational-specific warm-up incorporating the elements of motor control on the biomechanical aspects of the full golf swing. Thirty-six amateur golfers (mean ±SD age: 64 ± 8 years old; 75% male) were randomized into a Dynamic Rotation-Specific Warm-up group (n=20), or a Sham Warm-up group (n=16). X-Factor and X-Factor Stretch were measured at baseline and immediately following the warm-up. Mixed model ANCOVAs were used to determine if a Group*Time interaction existed for each variable with group as the between-subjects variable and time as the within-subjects variable. The mixed model ANCOVAs did not reveal a statistically significant group*time interaction for X-Factor or X-Factor Stretch. There was not a significant main effect for time for X-Factor but there was for X-Factor Stretch. These results indicate that neither group had a significant effect on improving X-Factor, however performing either warm-up increased X-Factor Stretch without significant difference between the two. The results of this study suggest that performing the Dynamic Rotation-Specific Warm-up did not increase X-Factor or X-Factor Stretch when controlled for age compared to the Sham Warm-up. Further study is needed to determine the long-term effects of the Dynamic Rotation-Specific Warm-up on performance factors of the golf swing while examining golfers across all age groups.
Cross-cultural Adaptation and Validation of the Korean Version of the Cumberland Ankle Instability Tool.
Authors: Ko J, Rosen AB, Brown CN
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The Cumberland Ankle Instability Tool (CAIT) is a valid and reliable patient reported outcome used to assess the presence and severity of chronic ankle instability (CAI). The CAIT has been cross-culturally adapted into other languages for use in non-English speaking populations. However, there are no valid questionnaires to assess CAI in individuals who speak Korean. The purpose of this study was to translate, cross-culturally adapt, and validate the CAIT, for use in a Korean-speaking population with CAI. The CAIT was cross-culturally adapted into Korean according to accepted guidelines and renamed the Cumberland Ankle Instability Tool-Korean (CAIT-K). Twenty-three participants (12 males, 11 females) who were bilingual in English and Korean were recruited and completed the original and adapted versions to assess agreement between versions. An additional 168 national level Korean athletes (106 male, 62 females; age =20.3±1.1 yrs), who participated in ≥ 90 minutes of physical activity per week, completed the final version of the CAIT-K twice within 14 days. Their completed questionnaires were assessed for internal consistency, test-retest reliability, criterion validity, and construct validity. For bilingual participants, intra-class correlation coefficients (ICC2,1) between the CAIT and the CAIT-K for test-retest reliability were 0.95 (SEM=1.83) and 0.96 (SEM=1.50) in right and left limbs, respectively. The Cronbach’s alpha coefficients were 0.92 and 0.90 for the CAIT-K in right and left limbs, respectively. For native Korean speakers, the CAIT-K had high internal consistency (Cronbach’s α=0.89) and intra-class correlation coefficient (ICC2,1 =0.94, SEM=1.72), correlation with the physical component score (rho=0.70, p=0.001) of the Short-Form Health Survey (SF-36), and the Kaiser-Meyer-Olkin score was 0.87. The original CAIT was translated, cross-culturally adapted, and validated from English to Korean. The CAIT-K appears to be valid and reliable and could be useful in assessing the Korean speaking population with CAI.
Sustained Isometric Shoulder Contraction on Muscular Strength and Endurance: A Randomized Clinical Trial.
Authors: Myers NL, Toonstra TL, Smith JS, Padgett CA, Uhl TL
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The Advanced Throwers Ten Exercise Program incorporates sustained isometric contractions in conjunction with dynamic shoulder movements. It has been suggested that incorporating isometric holds may facilitate greater increases in muscular strength and endurance. However, no objective evidence currently exists to support this claim. The purpose of this research was to compare the effects of a sustained muscle contraction resistive training program (Advanced Throwers Ten Program) to a more traditional exercise training protocol to determine if increases in shoulder muscular strength and endurance occur in an otherwise healthy population. It was hypothesized that utilizing a sustained isometric hold during a shoulder scapular plane abduction (scaption) exercise from the Advanced Throwers Ten would produce greater increases in shoulder strength and endurance as compared to a traditional training program incorporating a isotonic scaption exercise. Fifty healthy participants were enrolled in this study, of which 25 were randomized into the traditional training group and 25 were randomized to the Advanced Throwers Ten group. No pre-intervention differences existed between the groups (p>0.05). Arm endurance and strength data were collected pre and post intervention using a portable load cell (BTE Evaluator, Hanover, MD). Both within and between group analyses were performed in order to investigate average torque (strength) and angular impulse (endurance) changes. The traditional and Advanced Throwers Ten groups both significantly improved torque and angular impulse on both the dominant and non-dominant arms by 10-14%. There were no differences in strength or endurance following the interventions between the two training groups (p>0.75). The authors concluded that both training approaches increased strength and endurance as the muscle loads were consistent between protocols indicating that either approach will have positive effects.
Prevalence of Musculoskeletal Pain Among Swimmers Participants in an Elite National Tournament.
Authors: Almeida MO, Hespanhol LC, Lopes AD
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Professional swimmers are commonly affected by a high number of injuries due to their large amount of training. The occurrence of musculoskeletal pain during an important tournament has not been investigated. The objective of the study was to assess the prevalence of musculoskeletal pain and its characteristics in professional swimmers. Secondary objectives included evaluating the swimmers’ injury history over the previous 12 months, and examining the association of the presence of pain with personal and training characteristics of the swimmers. Two-hundred and fifty-seven swimmers who participated in the Brazilian Swimming Championship were included in the study and answered a questionnaire about personal and training characteristics, presence of pain, and injuries in the previous 12 months. The relative risk of presence of pain was calculated for the following variables: gender, BMI, stroke specialty, swimmer’s position, strength training, practice of another physical activity, and previous injuries. The prevalence of musculoskeletal pain was about 20%, with 60% of swimmers reporting at least one injury in the previous 12 months. The shoulder was the most commonly affected region and tendinopathy was the most common type of previous injury. No significant relationships were found between the presence of pain and personal or training characteristics. The results demonstrated that the prevalence of musculoskeletal pain in professional swimmers participating in the most important Brazilian national tournament was approximately 20%, while the majority of participants reported previous injuries in many areas.
High Repetition Jump Training Coupled with Body Weight Support in a Patient with Knee Pain and Prior History of Anterior Cruciate Ligament Reconstruction: A Case Report.
Author: Elias ARC, Kinney AE, Mizner RL
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Patients frequently experience long-term deficits in functional activity following anterior cruciate ligament reconstruction, and commonly present with decreased confidence and poor weight acceptance in the surgical knee. Adaptation of neuromuscular behaviors may be possible through plyometric training. Body weight support decreases intensity of landing sufficiently to allow increased training repetition. The purpose of this case report was to report the outcomes of a subject with a previous history of anterior cruciate ligament (ACL) reconstruction treated with high repetition jump training coupled with body weight support (BWS) as a primary intervention strategy. A 23-year old female, who had right ACL reconstruction seven years prior, presented with anterior knee pain and effusion following initiation of a running program. Following visual assessment of poor mechanics in single leg closed chain activities, landing mechanics were assessed using 3-D motion analysis of single leg landing off a 20 cm box. She then participated in an eight-week plyometric training program using a custom-designed body weight support system. The International Knee Documentation Committee Subjective Knee Form (IKDC) and the ACL-Return to Sport Index (ACL-RSI) were administered at the start and end of treatment as well as at follow-up testing. The subject’s IKDC and ACL-RSI scores increased with training from 68% and 43% to 90% and 84%, respectively, and were retained at follow-up testing. Peak knee and hip flexion angles during landing increased from 47° and 53° to 72° and 80° respectively. Vertical ground reaction forces in landing decreased with training from 3.8 N/kg to 3.2 N/kg. All changes were retained two months following completion of training. The subject experienced meaningful changes in overall function. Retention of mechanical changes suggests that her new landing strategy had become a habitual pattern. Success with high volume plyometric training is possible when using BWS. Clinical investigation into the efficacy of body weight support as a training mechanism is needed.
Distal Fibular Stress Fracture in a Female Recreational Runner: A Case Report with Musculoskeletal Ultrasound Imaging Findings.
Authors: Hoglund TL, Silbernagel KG, Taweel NR
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This case report describes a physical therapist’s use of diagnostic ultrasound imaging in the decision making process used to refer a patient to a physician for a suspected fibular stress fracture. The purpose of this case report is to 1) describe the history, subjective examination, and objective examination findings of a fibular stress fracture, 2) describe the ultrasound findings associated with a fibular stress fracture, and 3) describe the decision making process of a physical therapist in the decision to refer the patient to a medical physician for further work-up. A 52-year-old female recreational runner with a recent increase in running intensity self-referred to a physical therapist with a 19-day history of lateral lower leg pain. Examination revealed relatively normal ankle range of motion, mild weakness of ankle invertors and evertors, no increase in pain with resisted muscle tests of the ankle, and tenderness to palpation over the fibularis brevis muscle and distal fibula. Diagnostic ultrasound examination of the fibularis muscles revealed cortical irregularity of the distal third of the fibula in the location of tenderness. The physical therapist used the abnormal ultrasound findings, running history, symptoms, and physical examination for differential diagnosis, and decided to refer the patient to a physician for further examination. Radiographs revealed a fibular stress fracture. Follow-up ultrasound imaging demonstrated a mixed hypoechoic-hyperechoic appearance of the fibular cortex typical of healing fracture and the presence of bony callus. Diagnostic ultrasound imaging is increasingly being used by physical therapists to guide rehabilitation. Ultrasound imaging of musculotendinous structures may display adjacent bone. Physical therapists should be knowledgeable of normal and abnormal bony ultrasound imaging findings. Abnormal ultrasound findings may be one sign indicating the need to refer a patient for consultation by a physician.
Return to Hitting: An Interval Hitting Progression and Overview of Hitting Mechanics Following Injury.
Author: Monti R
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Participation in baseball is prevalent across all age groups. Baseball injuries are common and can impact a player’s ability to participate. An injury to any region can influence the player’s ability to swing the bat. As a part of the athlete's rehabilitation, a sports-specific program should be implemented that re-introduces the hitting cycle that addresses proper biomechanics as well as provides a progressive return to hitting. Although there are several return to throwing progression programs in the literature, to the author's knowledge no published hitting progression programs exist. Thus, the purpose of this clinical commentary is to propose a progressive return to hitting program that emphasizes proper mechanics for ballplayers who have sustained an injury. This clinical commentary describes in detail the phases of the baseball hitting cycle, as related to the return to hitting program. Important biomechanical information is provided on each phase that can be used to assist the clinician in injury prevention. This commentary provides the healthcare professional guidance for assessment for appropriate readiness for return to sport using impairment measures, patient-report measures, and physical performance measures. The purpose of this hitting progression is to provide a safe, gradual increase in hitting intensity by moving from a fixed position to soft toss and finally to increasing pitch velocity. This interval hitting program guides the clinician from when the patient is ready to begin hitting through a full return to sport. Use of appropriate hitting mechanics must be ensured during rehabilitation to avoid compensation. Similar to the return to throwing programs that exist, this interval hitting progression program can provide a framework to quantify progression and reduce the chance of re-injury during the return to sport phase of rehab.