Augmented and Intrinsic Feedback in Motor Learning of the Bodyweight Squat

Transcription

1 Augmented and Intrinsic Feedback in Motor Learning of the Bodyweight Squat Alexander J. Bedard This paper was completed and submitted in partial fulfillment of the Master Teacher Program, a 2-year faculty professional development program conducted by the Center for Faculty Excellence, United States Military Academy, West Point, NY, 2017 Abstract: The influence of augmented feedback (AF) on motor learning of the bodyweight squat and the development of intrinsic feedback (IF) was investigated. University students enrolled in physical education classes (n = 55) were assigned to one of three groups: a control group which received only modeling (CG), a verbal only feedback group (VO), and a verbal plus tactile feedback group (VT). Subjects were qualitatively assessed on performance of the bodyweight squat using a 0 to 6 scale. They were evaluated prior to instruction, immediately following acquisition, and on a retention trial 48 to 72 hours post-instruction. Acquisition consisted of 4 sets of 10 repetitions. A post-instruction survey was used to assess the development of IF. Both CG and VT significantly improved squat performance through instruction (p < 0.01) whereas VO did not. Only VT significantly improved squat performance during retention trials (p < 0.01). Perception of faults improved with increasing modes of AF (24% for CG, 42% for VO, 52% for VT). Pearson correlations between subject and instructor qualitative ratings were highest for VO (r = 0.70, p < 0.01), but were not significant for CG (r = 0.12, p = 0.60) or VT (r = 0.46, p = 0.55). The presence of AF will improve motor learning and is instrumental in the development of IF for basic fitness movements such as the body weight squat.

2 SQUAT 2 Augmented and Intrinsic Feedback in Motor Learning of the Bodyweight Squat Motor learning involves both psychomotor and cognitive aspects, distinguishing motor learning from traditional classroom learning and adding an additional layer of complexity (Newell, 1991). For example, an individual can factually know the steps for a correct golf swing, however being able to golf properly requires skills which cannot typically be gained from cognitive knowledge alone. Physical educators, coaches, and trainers use techniques and concepts in motor learning to accelerate the acquisition of motor skills and to enhance performance. One vital independent variable which can enhance motor learning is practicing a skill (Salmoni, Schmidt, & Walter, 1984). Most are familiar with the saying, practice makes perfect. Complex motor skills, however, are often more difficult to learn. Without the guidance of a coach, an individual may be doomed to repeat a skill incorrectly without ever learning how to properly execute the movement. This gives rise to the less well known saying attributed to Vince Lombardi: perfect practice makes perfect. Feedback. In order to achieve the concept of perfect practice, coaches, educators, and clinicians utilize the concept of feedback (Lee, Keh, & Magill, 1993). Feedback is simply information about the performance of a motor skill (Salmoni, Schmidt, & Walter, 1984; Lee, Swinnen, & Serrien, 1994). Feedback can be classified as intrinsic (IF), elements of performance that the individual gains without assistance, or extrinsic, also known as augmented feedback (AF) (Salmoni, Schmidt, & Walter, 1984). AF is information provided to an individual above what the individual can gain without assistance (Sigrist, Rauter, Riener, & Wolf, 2012; Lee, Swinnen, & Serrien, 1994). This can be provided as either knowledge of results (KR) or knowledge of performance (KP) (Newell, 1991). KR informs an individual about the outcome of the movement. An example of KR for throwing a ball would be how far the ball was thrown or if the intended target was reached. KR, however, does not provide information about technique flaws which may be useful in improving performance. KP, on the other hand, informs an individual about the quality of movement. An example for throwing a ball is a coach verbally telling a subject if the individual demonstrates sequential hip rotation before releasing the ball. Both KP and KR have been shown to enhance motor learning (Salmoni, Schmidt, & Walter, 1984; Lee, Swinnen, & Serrien, 1994; Newell, 1991). During the acquisition of a novel motor skill, however, KP is particularly beneficial (Rey, 1972). The practice of AF is one of the most researched concepts in motor learning (Lee, Keh, & Magill, 1993), and the ability to deliver timely and relevant augmented feedback distinguishes a world class coach from a novice. Modes of Augmented Feedback. Different modes of feedback can influence motor learning. Verbal feedback is the most commonly used type of feedback. This involves vocally giving information about an aspect of a motor skill (Landin, 1994; Lee, Keh, & Magill, 1993). Tactile feedback involves touching or physically manipulating an individual to achieve the desired motor pattern; tactile feedback can be administered by a coach or through instruments which guide or restrict motor patterns (Feygin, Keehner, & Tendick, 2002; Wolpert, Ghahramani, & Flanagan, 2001; Crespo & Reinkensmeyer, 2008). Visual feedback provides an individual with a video or image of a performance (Sigrist, Rauter, Riener, & Wolf, 2012). Auditory feedback provides an individual with acoustical information about a motor skill (Sigrist, Rauter, Riener, & Wolf, 2012; Konttinen, Mononen, Viitasalo, & Mets, 2004). Finally, multimodal feedback provides two or more modes of feedback to a learner. The most readily available modes of feedback to coaches, educators, and clinicians are verbal and tactile, as these modes of feedback require no additional resources. Single mode feedback has been the focus of much research to date, with limited studies investigating the effectiveness of combining forms of feedback. Research has shown that multimodal feedback may be more effective than single mode feedback. Combining learning modes may infer an enhancement to motor learning, motor performance, and skill retention, however there is a paucity of research on this topic (Sigrist, Rauter, Riener, & Wolf, 2012). Intrinsic Feedback. A learner acquires feedback naturally through many senses, including vision, audition, and proprioception. A vital role of AF is to naturally develop a subject s IF (Lee, Swinnen, & Serrien, 1994). This is an essential aspect of motor learning, as an individual needs to adequately perform the skill without assistance (Lee, Swinnen, & Serrien, 1994). Frequently provided

3 SQUAT 3 feedback may actually impair an individual s development of intrinsic feedback and subsequently reduce motor learning and performance (Lee, Swinnen, & Serrien, 1994; Swinnen, Nicholson, Schmidt, & Shapiro, 1990). This phenomena has been studied extensively and is known as the guidance hypothesis (Lee, Swinnen, & Serrien, 1994; Salmoni, Schmidt, & Walter, 1984; Winstein & Schmidt, 1990). An aspect of IF which has not been researched to the knowledge of the author is the question of how well instructional strategies develop IF. This is particularly important as coaching is not always available or feasible. Application to Fitness Education. While the research involving motor learning and augmented feedback is broad and diverse, most research has focused on simple motor skills. Very little research has been conducted on motor learning for movements involved in fitness programs (Rucci & Tomporowski, 2010). Learning and executing proper motor patterns of general fitness movements will lead to increased work output through greater movement efficiency, and will serve to reduce injury potential from improper or unsafe movement. The squat is one foundational fitness movement with applications for jumping, landing, and safely lifting objects using the lower extremities and core. The squat also has applications to military operations, and is the focus of many activities in the Army s Physical Readiness Training (Department of the Army, 2012). Rehabilitation programs commonly rely on the squat, and this movement is considered one of the best exercises for improving quality of life (Schoenfeld, 2010). Despite being an integral movement in many fitness programs, little research exists on instruction of the basic squat in a classroom setting. Knowledge of the influence of instructional strategies on learning the squat can be beneficial to coaches, instructors, and clinicians. Most studies of AF have focused on motor learning conducted in isolation versus that conducted in a typical classroom environment (Landin, 1994), and there is a lack of research on the effectiveness of AF in developing intrinsic feedback. The present investigation will therefore study the effect of AF on motor learning of the bodyweight squat in a group instruction setting. Method Subjects. A total of 55 cadets were sampled from physical fitness classes at the United States Military Academy at West Point, NY. Subjects ranged in age from 21 to 26. Classes were randomly assigned a treatment, and all subjects from one class received the same treatment. Descriptive statistics for each of the three groups are presented in Table 1. No differences were observed among groups according to BMI, APFT scores, or prior experience or instruction with the squat. Procedure Experimental Approach. A mixed-model research design was used in which classes were randomly assigned to one of three groups: control (CG) in which no feedback was provided, a verbal only feedback only group (VO), and a verbal plus tactile feedback group (VT). Subjects were assessed on the squat. Groups received instruction and were re-assessed following the completion of an acquisition period. A retention trial was conducted 48 to 72 hours after the acquisition period. Subjects were also surveyed about their experience with the squat, perceptions of their performance, and asked to identify areas of the squat they need to improve (Appendix C). It was hypothesized that the group receiving no feedback would underperform when compared to either VO or VT, and that VT would yield greater movement proficiency than VO. It was also hypothesized that greater feedback would improve subject perception of squat performance and subject knowledge of motor skill deficiencies. Standards of Movement. There is no widely accepted standard for proper execution of the squat. Variations on stance, depth, and torso inclination are common distinctions (Clark, Lambert, & Hunter, 2012; Schoenfeld, 2010). While many organizations have standardized instruction of the weighted squat, the focus of the present investigation was the bodyweight squat. As such, the following movement standards where adopted based on a review of relevant literature (Clark, Lambert, & Hunter, 2012;

4 SQUAT 4 Comfort & Kasim, 2007; Schoenfeld, 2010; Snarr & McGinn, 2015; Chandler & Stone, 1991). The stance for the squat is approximately shoulder width, with feet roughly parallel to each other. Feet may be toed out slightly (up to 30 degrees). The heels of the feet must remain in contact with the ground throughout the entirety of the movement. The movement begins at complete hip and knee extension. The hips, knees, and ankles are then flexed until the crease formed by the hip joint descends below the top of the patella when viewed from the sagittal place. The knees should track in line with the angle of the feet when viewed from either the frontal or transverse plane. The back and the neck should remain in a neutral position throughout the entire movement. Once proper depth is achieved, the ankles, knees, and hips are extended until the starting position is once again achieved. Qualitative Analysis. In order to objectively assess motor learning of the squat, qualitative analysis was utilized as described by Knudson and Morrison (1996). Based on the aforementioned standards of movement, 6 qualitative components were identified and used to create a scoring system similar to that used by Herrington and Munro (2014) (see Appendix A). Each component was scored as a 1 if properly demonstrated, and a 0 if improperly demonstrated for a best possible score of 6. The assessment item used is displayed in Appendix B. All subjects were scored in real time by the same rater. Instruction. Each group received a block of instruction followed by an acquisition period of 4 sets of 10 repetitions. All groups received a standardized overview of the purpose of the squat along with the components of the squat. The VO group then received instruction on common faults and the corresponding verbal corrections, while the VT group received instruction on common faults and both verbal and tactile corrections. When performing acquisition trials, the control group imitated the instructor who served as a model with no further coaching or corrections. The VO and VT groups were randomly assigned another subject as a coach who issued corrections according to the treatment. For both the VO and VT groups, the instructor circulated and made additional corrections according to the treatment prescribed for the group. Intrinsic Feedback. In order to gauge the development of intrinsic feedback, immediately following the post-test subjects were queried on self-perception of their performance. Subjects rated their performance on a 1 to 10 scale, with a 10 being a perfect squat demonstrating all components. Subjects were also queried as to which areas of the squat still required improvement in order to achieve mastery. Statistical Analysis. A two way ANOVA (treatment x time) was used to evaluate instruction effectiveness. Treatment included three levels (CG, VO, VT), while time also included three levels (pretest, post-test, retention). The Holm-Sidak method was used for post hoc comparisons. Paired t tests were used to evaluate performance of individual components within groups. Significance levels were determined a priori to be In order to evaluate the development of intrinsic feedback Pearson correlations were conducted between observed post-test qualitative scores and subject perceived performance. Observed post-test scores were transformed to a 1 to 10 scale for comparison. Results Instruction Effectiveness. A natural logarithmic transformation was used on qualitative scores in order to evaluate the effectiveness of instruction as the original data set failed the Brown-Forsythe equal variance test (p < 0.05). The transformed data failed the Shapiro-Wilk normality test (p < 0.05), however data passed the equal variance test (p = 0.11). The decision was made to continue with the two way ANOVA due to the robustness of the test. A main effect was observed for treatment, F(2,55) = 5.85, and time, F(2,55) = 12.68, but not treatment x time, F(4,55) = Post hoc comparisons are displayed in Table 2. There were significant differences on the pre-test between CG and VO (p = 0.02), between VO and VT (p = 0.02), but not VT and CG (p = 0.95). In evaluating instruction effectiveness, post hoc comparisons revealed significant differences for pre and post trials for CG (p < 0.01, Figure 1) and VT (p < 0.01, Figure 3), but not VO (p = 0.35, Figure 2). VT also exhibited a significant difference between pretest and retention trials (p < 0.01, Figure 3). CG demonstrated a significant increase in scores on the knees component only (p < 0.01, Figure 4). VO did not significantly improve any individual qualitative

5 SQUAT 5 components (Figure 5). VT significantly improved the knees (p < 0.01) and hips (p < 0.01) component, but not any other individual components (Figure 6). Development of Intrinsic Feedback. Intrinsic feedback results are displayed in Table 3. Pearson product moment correlations revealed a significant correlation between qualitative scores and subject ratings for the VO group (r = 0.70, p < 0.01), but not for CG (r = 0.12, p = 0.60) or VT (r = 0.46, p = 0.06). Subjects were also queried and scored on their perception of faults. CG demonstrated the lowest accuracy, with only 24% correctly identifying their faults on the post-test. Performance on perception increased with additional modes of feedback, with 42% of VO and 52% of VT correctly self-identifying faults. Discussion Fitness Movements as Motor Skills. The results of the present study lend further evidence that foundational fitness movements can be taught and learned as motor skills. To the knowledge of the author only three other studies exist in the literature utilizing motor learning strategies to teach and assess fitness movements. McCullagh and Meyer (1997) also demonstrated that AF could improve motor learning of a foundation fitness movement the squat lift. Although those authors used a different fitness movement, McCullagh and Meyer (1997), employed a similar qualitative analysis method with scores ranging from 1 to 5. Performance improvements due to treatments, which were similar to what was observed in the present study, averaged around 0.5 to 1 performance point. The remaining two studies involving motor learning and fitness movements involve the power snatch and the hang power clean. These movements are much more complex than either the bodyweight squat utilized in the present study or the squat lift utilized by McCullagh and Meyer (1997). Nevertheless, comparisons can still be drawn among studies. Winchester, Porter, and McBride (2009) assessed how both kinematic and kinetic variables were altered in response to AF, finding that only the AF group improved performance. This observation is in contrast to the present study in which the control group also improved performance. The control group in Winchester et al. (2009), however, received no instruction whatsoever whereas in the present study the control group was able to watch a model perform the skill correctly during skill acquisition. Based on the results of Winchester et al. (2009), it could be hypothesized that absent a model, the control group in the present study may not have improved performance. Rucci and Tomporowski (2010) measured kinematic variables of the hang power clean in response to different modes of feedback. Groups which received AF in the form of verbal cues were able to significantly improve qualitative performance of the movement. The aforementioned studies all support the findings of the present investigation which provide evidence that the performance of fitness movements can be improved via AF. Influence of Modeling on Motor Learning. In contrast to what was hypothesized, the results of the present study demonstrate that modeling alone is as effective as instruction utilizing different modes of AF during skill acquisition. This is supported by the fact that were was no observed treatment x time interactions. Based on literature describing effective motor learning strategies (Lee, Keh, & Magill, 1993; Salmoni, Schmidt, & Walter, 1984; Lee, Swinnen, & Serrien, 1994), it was thought that CG would underperform when compared to groups with AF. These results lend evidence to the importance of providing a correct model for students to emulate when attempting to learn fitness movements. While modeling was as effective as AF during motor skill acquisition, modeling alone demonstrated the lowest performance on retention trials. This lends evidence to the notion that AF will improve long term motor learning when compared to instruction in which AF is absent. The only group which demonstrated significant improvement during retention trials when compared to the pre-test was the VT group. It can be hypothesized that this effect may also have been observed in the VO group if the pre-test scores of this group were similar to those of CG and VT. These data provide evidence that although modeling alone is effective during skill acquisition, in order to improve motor learning, AF should be used.

6 SQUAT 6 Development of Intrinsic Feedback. Another concern of motor learning strategies is the development of IF. A clear positive trend was observed in the present study with regards to subject selfperception of faults during post-test performance and increasing modes of AF. This is important in motor learning, as subjects cannot improve performance of a motor skill unless they are aware of any components which are being performed incorrectly. At the present time there does not appear to be any motor learning studies which have evaluated the development of IF to draw comparisons. The present study also measured subject self-perception by having subjects rate their performance during the post-test. The CG demonstrated no correlation between self-score and qualitative score, whereas VO showed a clear positive and significant correlation. This demonstrates that without the presence of AF, subjects have limited perception of their ability to correctly execute a motor skill. Although the VT group did not demonstrate a significant correlation between self-perception and qualitative scores, the values were approaching significance. It can be argued that with more power a correlation could be observed. The strength of the correlation observed in VT was less than that observed in VO, which may be explained by an over-abundance of AF. Too much AF can actually impair skill acquisition, retention, and the development of IF (Lee, Swinnen, & Serrien, 1994; Salmoni, Schmidt, & Walter, 1984; Swinnen, Nicholson, Schmidt, & Shapiro, 1990; Winstein & Schmidt, 1990). A final observation of the performance of subjects in all groups is that the back component proved to be the most difficult for subjects to attain regardless of treatment (CG = 35%, VO = 47%, VT = 28%). This could be due to flexibility limitations which cannot be fixed in a single session (Chandler & Stone, 1991). Performing this component correctly, however, is extremely important if athletes intend to progress to weighted variations of the squat, as spinal flexion during squatting is linked to many back related injuries (Chandler & Stone, 1991; Schoenfeld, 2010). Limitations One of the main limitations of the present study is that the VO group demonstrated significantly higher pre-test qualitative scores than either CG or VT. This was not controlled by the experimental design as subjects were sampled in physical education classes. This difference may help explain the failure of the VO group to demonstrate significant improvement of qualitative scores on either the posttest or the retention trial when compared to the pre-test. This also limited comparisons which could be made between AF conditions, as there is considerable debate as to how much or what modes of AF will results in greater skill acquisition, retention, and the development of IF. Another limitation of the present study was that the rater was not blind to the experimental conditions of any groups. This may have introduced sub-conscious bias when evaluating qualitative scores for groups. A better design would be to use a rater who has no knowledge of the experiment or treatments given to groups, and who is only utilized to objectively assess qualitative performance. An alternative option would be to use kinematic analysis through video software, such as that used by Herrington and Munro (2014), Rucci and Tomporoswki (2010), or Winchester et al. (2009). Conclusions The presence of AF is instrumental in the development of IF for instruction of basic fitness movements such as the body weight squat. While using a correct model during skill acquisition is important and will result in acceptable performance improvements through acquisition, the presence of AF will improve long term motor learning as measured through retention trials. Physical educators, coaches, and physical therapists should utilize proper models and AF when instructing fitness movements to enhance and accelerate motor learning.

7 SQUAT 7 References Chandler, T. J., & Stone, M. H. (1991). The squat exercise in athletic conditioning: a review of the literature. National Strength and Conditioning Association Journal, 13(5), Clark, D. R., Lambert, M. I., & Hunter, A. M. (2012). Muscle activation in the loaded free barbell squat: a brief review. Journal of Strength and Conditioning Research, 26(4), Comfort, P., & Kasim, P. (2007). Optimizing Squat Technique. Strength and Conditioning Journal, 29(6), Crespo, L. M., & Reinkensmeyer, D. J. (2008). Haptic guidance can enhance motor learning of a steering task. Journal of Motor Behavior, 40(6), Department of the Army. (2012, October 26). FM 7-22: Army Physical Readiness Training. Washington, D.C., United States of America. Feygin, D., Keehner, M., & Tendick, R. (2002). Haptic guidance: Experimental evaluation of a haptic training method for a perceptual motor skill. Haptic Interfaces for Virtual Environment and Teleoperator Systems, Herrington, L., & Munro, A. (2014). A preliminary investigation to establish criterion validity of a quanlitative scoring system of limb alignment during single leg squat and landing. Journal of Exercise, Sports & Orthopedics, 1(2), 1-6. Knudson, D., & Morrison, C. (1996). An integrated qualitative analysis of overarm throwing. Journal of Physical Education, Recreation, and Dance, 67(6), Konttinen, N., Mononen, K., Viitasalo, J., & Mets, T. (2004). The Effects of Augmented Auditory Feedback on Psychomotor Skill Learning in Precision Shooting. Journal of Sport & Exercise Physiology, 26, Landin, D. (1994). The role of verbal cues in skill learning. QUEST, 46, Lee, A. M., Keh, N. C., & Magill, R. A. (1993). Instructional effects of teacher feedback in physical education. Journal of Teaching in Physical Education, 12, Lee, T. D., Swinnen, S. P., & Serrien, D. J. (1994). Cognitive effort and motor learning. QUEST, 46, Newell, K. M. (1991). Motor skill acquisition. Annual Review of Psychology, 42, Rey, P. D. (1972). Appropriate feedback for open and close skill acquisition. QUEST, 17(1), Rucci, J. A., & Tomporowski, P. D. (2010). Three types of kinematic feedback and the execution of the hang power clean. Journal of Strength and Conditioning Research, 24(3), Salmoni, A. W., Schmidt, R. A., & Walter, C. B. (1984). Knowledge of results in motor learning: a review and critical appraisal. Psychological Bulletin, 95(3), Schoenfeld, B. J. (2010). Squatting kinematics and kinetics and their application to exercise performance. Journal of Strength and Conditioning Research, 24(12), Sigrist, R., Rauter, G., Riener, R., & Wolf, P. (2012). Augmented visual, auditory, haptic, and multimodal feedback in motor learning: a review. Psychological Bulletin & Review, 20(1), Snarr, R. L., & McGinn, W. (2015). Addressing weaknesses in squat patterns. Journal of Sport and Human Performance, 3(1), 1-12.

8 SQUAT 8 Swinnen, S. P., Nicholson, D. E., Schmidt, R. A., & Shapiro, D. C. (1990). Information feedback for skill acquisition: instantaneous knowledge of results degrades learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 16(4), Winstein, C. J., & Schmidt, R. A. (1990). Reduced frequence of knowledge of results enhances motor learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 16(4), Wolpert, D. M., Ghahramani, Z., & Flanagan, J. R. (2001, November). Perspectives and problems in motor learning. TRENDS in Cognitive Sciences, 5(11),

9 SQUAT 9 Table 1 Demographics Group Age (yrs) BMI (kg m -2 ) APFT Previous Years Instruction Training (yrs) CG 21.8 ± ± ± % 3.9 ± 3.3 VO 21.7± ± ± % 4.5 ± 3.3 VT 21.8 ± ± ± % 4.0 ± 0.2 Note. CG = Control Group. VO = Verbal Only. VT = Verbal Tactile. No significant differences exist between groups. Table 2 Qualitative Performance of the Squat Group Component Pre-Test Post-Test Retention CG * 4.32 Stance 90% 100% 95% Heels 60% 80% 79% Knees 40% 80%* 58% Hips 50% 75% 63% Stand 90% 95% 100% Back 40% 35% 37% VO Stance 88% 94% 94% Heels 94% 100% 100% Knees 82% 100% 88% Hips 59% 71% 75% Stand 94% 88% 94% Back 29% 47% 56%* VT * 4.17* Stance 89% 100% 94% Heels 100% 100% 100% Knees 28% 72%* 94%* Hips 39% 89%* 56% Stand 94% 100% 100% Back 22% 28% 25% Notes. CG = Control Group; VO = Verbal Only; VT = Verbal Tactile; * = Significantly different from pre-test within group (p < 0.01); = Significantly different from VO (p < 0.05)

10 SQUAT 10 Table 3 Development of Intrinsic Feedback Group Subject Self-Rating Perception of And Qualitative Score Faults Correct CG r = 0.12 (p = 0.60) 24% VO r = 0.70 (p < 0.01) 42% VT r = 0.46 (p = 0.06) 52% Note. CG = Control Group. VO = Verbal Only. VT = Verbal Tactile. Figure 1. Qualitative performance scores of CG. Individual subject scores are annotated with dashed lines, whereas CG mean scores are annotated by the solid line and solid dots. Note. *Significantly different from pre-test values (p < 0.05)

11 SQUAT 11 Figure 2. Qualitative performance scores of VO. Individual subject scores are annotated with dashed lines, whereas VO mean scores are annotated by the solid line and solid dots. * Figure 3. Qualitative performance scores of VT. Individual subject scores are annotated with dashed lines, whereas VT mean scores are annotated by the solid line and solid dots. Note. *Significantly different from pre-test values (p < 0.05)

12 SQUAT 12 * * Figure 4. CG qualitative performance of individual components of the squat throughout trials. Note. *Significantly different from pre-test values (p < 0.05) Figure 5. VO qualitative performance of individual components of the squat throughout trials.

13 SQUAT 13 * * * * Figure 6. VT qualitative performance of individual components of the squat throughout trials. Note. *Significantly different from pre-test values (p < 0.05)

14 SQUAT 14 Appendix A Qualitative Components of the Squat 1. Stance. The subject will assume a roughly shoulder width stance. The toes will be oriented directly forward or canted externally up to 30 degrees. A stance which is too narrow (hip width) or excessively wide (greater than shoulder width) will not receive credit. An inward rotation of the toes or a rotation of the toes externally 45 degrees or greater will receive no credit. 2. Heels. The entire bottom of the foot will remain in full contact with the ground throughout the movement. Any portion of the sole of the shoe losing contact with the ground will receive no credit. 3. Knees. The knees will track in line with the orientation of the foot throughout the squat movement. Any inward collapsing of the knees, or a valgus movement, will receive no credit. 4. Hip Depth. The subject will descend until the crease formed by the torso and the upper thigh clearly descends below the uppermost portion of the knee joint when viewed from the sagittal plane. Failure to clearly demonstrate that the crease of the hip is below the knee will receive no credit. 5. Hip Extension. After squatting, the subject will extend the knees and hips until both joints reach full extension and the subject is standing fully erect. Failure to fully return to the starting position before initiating a subsequent repetition will receive no credit 6. Back. The back will remain in a neutral position throughout the movement, maintaining the natural curvature of the spine. Any observed flexion of the spine or excessive extension will receive no credit.

15 SQUAT 15 Appendix B Squat Assessment Item Squat Assessment Item Group: Date: Pre/Post # Control Number Stance 2. Heels 3. Knees 4. Hip Depth 5. Hip Extension 6. Back Comments

16 SQUAT 16 Appendix C Subject Post-Test Survey Control Number: Age: Gender: M/F Height: Weight: Have you ever had professional instruction on the squat (coach, trainer, therapist, etc.)? Y/N Do you use the squat in your general fitness routines? Y/N Approximately how many years have you been training the squat? Did you pay varsity level high school sports? Y/N Rate your performance on the squat today from 1-10, with 10 being an absolutely perfect squat: What area(s) of your squat need improvement? (If the following is unknown, leave blank) APFT Push Ups: Push Up Score: APFT Sit Ups: Sit Up Score: APFT 2 Mile Run: 2 Mile Run Score: