Validity and reliability of a low-cost dynamometer to assess maximal isometric strength of upper limb

Muscle imbalance and deficit are key parameters for guiding rehabilitation and sports sessions and avoiding injuries. However, the high cost and non-portable nature of most instruments employed for muscle strength assessment frequently hamper an affordable evaluation in field conditions. This study evaluated the validity and reliability of a low-cost digital dynamometer to assess the maximal isometric strength of upper limb muscles. Fourteen physically active volunteers performed the main movements of the upper limb at maximal isometric strength: flexion-extension, internal-external rotation and abduction-adduction of the shoulder; and flexion-extension of both elbow and wrist. Validity was examined by comparing the strength values from the low-cost digital dynamometer and those measured by an isokinetic dynamometer, assumed as the gold standard. The correlation between both devices was perfect (r > 0.913), while Bland-Altman plots showed absolute agreement between both devices, the maximum range of the values of bias was ?0.99–1.00 N in wrist extension. Inter-tester and intra-tester reliability were excellent for all movements (ICC ≥ 0.855). The low-cost digital dynamometer showed strong validity and excellent reliability in assessing maximal isometric strength during the main movements of the upper limb. Professionals may use it for an affordable isometric muscle strength assessment in field situations.     

Examining the influence of grip type on wrist and club head kinematics during the golf swing: Benefits of a local co-ordinate system

Wrist movements have been identified as an important factor in producing a successful golf swing, with their complex motion influencing both club head velocity and orientation. However, a detailed analysis of wrist angles is lacking in the literature. The purpose of this study was to determine kinematics across wrists and club head characteristics during the golf swing under weak, neutral and strong grip conditions. Twelve professional male golfers executed 24 shots using a driver under three grip conditions. A six degrees of freedom analysis of the hand with respect to the distal forearm was performed using a 10-camera three-dimensional motion capture system. Differences in joint angles were explored using repeated measures ANOVAs at key swing events (onset, top of backswing and impact), in addition club head velocity and clubface angle at impact were also explored. Main findings revealed significant differences in flexion/extension and internal/external rotation for both wrists at all swing events, whereas fewer significant interactions were found in ulnar/radial deviation across grips for both wrists at all events. Clubface angle only differed significantly between the weak and the strong and neural grips, presenting a more ‘open’ clubface to the intended hitting direction. This study is the first to explore tri-planar wrist movement and the effect of different grips, such analysis has implications for coaching knowledge and practice and should inform future research into different aspects of skill, technique analysis and may inform injury mechanisms/prevention.     

Exposing athletes to playing form activity: outcomes of a randomised control trial among community netball teams using a game-centred approach

This study evaluated whether exposing junior netball players to greater amounts of competition relevant activity (playing form activity) had an effect on game play outcomes and session involvement. A group-randomised controlled trial in one junior netball club in the Hunter Region, NSW, Australia. Ninety female athletes (mean age = 9.04 years, SD 1.53) were randomised by team (n = 11) into the intervention (n = 41) or 9-week wait-list control (n = 49) condition. The Professional Learning for Understanding Games Education into Sport (PLUNGE into Sport) programme was undertaken in the first half of nine training sessions (9 × 30 min). The intervention exposed athletes to playing form activity through a coach development programme within training sessions. Athletes’ decision-making, support and skill outcomes during a small-sided invasion game, and session involvement (pedometer step/min), were measured at baseline and 9-week follow-up. Linear mixed models revealed significant group-by-time intervention effects (P < 0.05) for decision-making (d = 0.4) and support (d = 0.5) during game play, and in-session activity (d = 1.2). An intervention exposing athletes to greater levels of playing form activity, delivered via a coach education programme, was efficacious in improving athlete decision-making and support skills in game play and increasing athlete involvement during sessions.     

Sports’ disciplinary legacy and the challenge of ‘coaching differently’

Be empowering. Be athlete-centered. Be autonomy supportive. These are three related topics currently being promoted by sport psychologists and sport pedagogists in an effort to recognize athletes’ unique qualities and developmental differences and make coaching more holistic and coaches more considerate. This has led us to ask, how likely are such initiatives to lead to coaches putting their athletes at the center of the coaching process given that coaches’ practices have largely been formed through relations of power that subordinate and objectify athletes’ bodies through the regular application of a range of disciplinary techniques and instruments [e.g. Barker-Ruchti, N., &; Tinning, R. (2010). Foucault in leotards: Corporeal discipline in women's artistic gymnastics. Sociology of Sport Journal, 27, 229–250; Heikkala, J. (1993). Discipline and excel: Techniques of the self and body and the logic of competing. Sociology of Sport Journal, 10, 397–412; Gearity, B., &; Mills, J. P. (2012). Discipline and punish in the weight room. Sports Coaching Review, 1, 124–134]? In other words, to try to develop athlete-centered coaches capable of coaching in ways that will empower their athletes without also problematizing the discursive formation of coaches’ practices concerns us [Denison, J., &; Mills, J. P. (2014). Planning for distance running: Coaching with Foucault. Sports Coaching Review, 3, 1–16]. Put differently: how can athlete empowerment initiatives be anything more than rhetoric within a disciplinary framework that normalizes maximum coach control? It is this question that we intend to explore in this paper. More specifically, as Foucauldians, we will argue that coaching with greater consideration for athletes’ unique qualities and developmental differences needs to entail coaching in a less disciplinary way and with an awareness and appreciation of the many unseen effects that disciplinary power can have on coaches’ practices and athletes’ bodies.     

Book review

The following books are reviewed.

Value and validity in action research: a guidebook for reflective practitioners EILEEN M. SCHWALBACH (2003) London: Scarecrow Press 121 pp., ISBN 1 57886 017 2 (pb), £10.22

Supporting Teachers, Supporting Pupils D.F. WILSON, 2004 London: RoutledgeFalmer 184 pp., ISBN 0 415 33522 1 (hb), £65, 0 415 33523 X (pb), £22.50